CN108930072B

CN108930072B - Flame-retardant antistatic polypropylene fiber composition and fiber and non-woven fabric prepared from same

Info

Publication number: CN108930072B
Application number: CN201710371677.XA
Authority: CN
Inventors: 郭鹏; 吕明福; 徐耀辉; 张师军; 杨芝超; 初立秋; 李�杰; 徐萌; 尹华; 邹浩; 杨庆泉
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2017-05-24
Filing date: 2017-05-24
Publication date: 2021-07-02
Anticipated expiration: 2037-05-24
Also published as: CN108930072A

Abstract

The invention provides a flame-retardant antistatic polypropylene fiber composition, which comprises the following components in parts by weight: 75-95 parts of flame-retardant antistatic polypropylene composition and 5-25 parts of polyolefin and/or elastomer; 0.01-0.25 part of slipping agent; wherein the flame retardant antistatic polypropylene composition comprises a flame retardant comprising a complex of a phosphine oxide and a transition metal salt. The invention also provides flame-retardant antistatic polypropylene fibers prepared by the flame-retardant antistatic polypropylene fiber composition through a spun-bonded spinning method and flame-retardant antistatic polypropylene non-woven fabrics prepared from the fibers. The flame-retardant antistatic polypropylene non-woven fabric provided by the invention has the advantages of good filtering performance, small residual deformation, good touch feeling and flame-retardant antistatic performance.

Description

Flame-retardant antistatic polypropylene fiber composition and fiber and non-woven fabric prepared from same

Technical Field

The invention belongs to the technical field of processing of high polymer materials and plastics, and particularly relates to a flame-retardant antistatic polypropylene fiber composition, and fibers and non-woven fabrics prepared from the same.

Background

Polypropylene resin is widely used for manufacturing non-woven fabrics due to its excellent mechanical processing formability, mechanical properties, high heat resistance, high cost performance and recyclability, and is applied to the fields of medical hygiene (medical masks and surgical gowns), labor protection and personal protection (dust masks and air purifier filter elements), personal hygiene products (sanitary napkins, diapers and cotton wet wipes), and the like.

Among them, in recent years, society has a high demand for filterability of nonwoven fabric products in the fields of environmental protection (e.g., PM2.5 protection) and health and hygiene (infectious diseases can be transmitted by air droplets, such as H1N1 and H5N 6). For example, a non-woven N95 type mask is a particle-proof mask certified by NIOSH (national institute of occupational safety and health). "N" means particles not suitable for oiliness; "95" means that the filtration efficiency is 95% under the test conditions specified in the NIOSH standard. Products that meet the N95 standard and pass the NIOSH review may be referred to as "N95 type masks". The N95 mask has the greatest characteristic of preventing droplet infection caused by splashing of body fluid or blood of a patient. The size of the spray is 1-5 microns in diameter. The united states Occupational Safety and Health Administration (OSHA) prescribes that medical personnel exposed to tuberculosis bacteria must wear masks above the N95 standard. The filtering efficiency reaches 95%, and the realization means mainly comprises: the mesh density of the non-woven fabric is increased, and the multi-layer composite non-woven fabric is used and added with an adsorbent such as activated carbon. Wherein, the mesh density of the non-woven fabric is improved in the most simple mode, the production cost is improved in a lower way, and the process is simple and convenient. The primary means of achieving an increase in the mesh density of the nonwoven fabric is to reduce the nonwoven fabric tow denier, i.e., to use finer tows.

The industrial production of finer tows is mainly obtained by adjusting the molecular weight distribution of polypropylene, i.e. reducing the width of the molecular weight distribution of polypropylene. The process for preparing narrow molecular weight distribution polypropylene is usually achieved by peroxide degradation, but in addition to the increased production costs associated with the use of peroxides, the residual peroxide also tends to cause odor in the final product, which affects the use of nonwoven products. Therefore, in order to improve the performance of polypropylene products and expand the application field, people begin to pay attention to the development of new products of polypropylene with narrow molecular weight distribution so as to meet the requirements of different fields on polypropylene resin. The polypropylene with narrow molecular weight distribution has wider Newtonian plateau region in the flowing process, the viscosity fluctuation with the change of shear rate is smaller, and the extrusion amount is easier to control stably. Since raw fiber products of nonwoven fabrics generally require polymers having improved physical-mechanical properties such as flexural strength, impact resistance and heat distortion resistance, it is necessary to produce them from polypropylene resins having a narrow molecular weight distribution. In the aspect of spinning application, if the molecular weight distribution of polypropylene is controlled to be narrow, the stability of the pressure of a spinning nozzle can be improved, and the fineness and the uniformity of the spun filaments are ensured.

The molecular weight distribution of the polymer is directly influenced by the properties of the catalyst employed in the polymerization. For example, the use of metallocene catalysts enables the production of narrow molecular weight distribution polypropylenes having a molecular weight distribution of from 2.3 to 2.7. Because the oligomer content is obviously reduced, the peculiar smell generated in the processing process of the resin can be reduced, and the material performance is also obviously improved. However, the metallocene catalyst is expensive in supported cost, and the supported catalyst has low activity, which limits the application range to a certain extent. Compared with metallocene catalyst, the molecular weight distribution of polypropylene prepared by Ziegler-Natta catalyst is wider, MWD range is generally between 5-7, but it has the advantages of low cost, high catalytic activity and the like, so that the preparation of high-activity supported Ziegler-Natta catalyst and the obtaining of polypropylene with excellent material performance and narrow molecular weight distribution have wide application prospect.

In recent years, various research institutes at home and abroad have studied the influence of the Ziegler-Natta catalyst component, the polymerization condition and the like on the molecular weight distribution of polypropylene. Chinese patents CN103788259, CN103788260 and CN104250395 disclose a polypropylene with narrow molecular weight distribution and a preparation method thereof. Characterized in that when the Ziegler-Natta catalyst preferably contains R¹”_m”R²”_n”Si(OR³”)_4-m”_-n"means that a propylene polymer having a narrow molecular weight distribution is directly produced by reactor polymerization under the condition that an organosilicon compound is an external electron donor.

It is noted that flame retardant and antistatic properties are also a concern when nonwoven fabrics are used for medical and interior applications. Polypropylene has poor antistatic property, static charges are easily generated when the polypropylene is rubbed with the outside, and the charges are not easy to leak out and are continuously accumulated on the surface. After the polypropylene surface is charged, if the surface is not effectively treated or antistatic treated, dust and dirt in the air can be adsorbed. When a human body contacts polypropylene with static electricity, the human body can generate electric shock feeling, the static electricity can also cause misoperation of electronic equipment, and more seriously, the static electricity accumulation can generate electrostatic attraction (or repulsion), electric shock or spark discharge phenomena, which can cause huge disasters under the environment conditions of inflammable and explosive substances. To avoid the effects of static electricity, polypropylene must be antistatic modified to suit certain special applications. For example, when the nonwoven fabric is used in surgical gowns, certain antistatic properties must be considered in order to avoid interference of static electricity with medical instruments and artificial devices such as cardiac pacemakers. Polypropylene inflammable substance has large heat value during combustion and is accompanied with molten drops, so that flame is easy to spread. For example, when the nonwoven fabric is used for automobile interior or interior materials, it must be considered to have a certain flame retardancy.

Therefore, there is a problem that research and development of a flame retardant antistatic polypropylene fiber composition and a fiber and a non-woven fabric prepared therefrom are urgently needed.

Disclosure of Invention

The invention aims to solve the technical problem of providing a flame-retardant antistatic polypropylene fiber composition and a fiber and a non-woven fabric prepared from the same aiming at the defects of the prior art. The flame retardant and the antistatic agent adopted in the flame-retardant antistatic polypropylene fiber composition provided by the invention can generate a synergistic effect, and simultaneously, the flame retardant performance and the antistatic performance are improved. The flame-retardant antistatic polypropylene fiber is prepared by taking the flame-retardant antistatic polypropylene fiber composition as a raw material, and the flame-retardant antistatic polypropylene non-woven fabric prepared from the fiber has the advantages of good filtering performance, small residual deformation, good touch feeling and good flame-retardant antistatic performance.

To this end, the first aspect of the present invention provides a flame retardant antistatic polypropylene fiber composition, which comprises the following components in parts by weight:

75-95 parts of flame-retardant antistatic polypropylene composition, preferably 80-90 parts;

5-25 parts, preferably 10-20 parts, of polyolefin and/or elastomer;

0.01-0.25 part of slipping agent, preferably 0.02-0.2 part.

Wherein the flame retardant antistatic polypropylene composition comprises a flame retardant comprising a complex of a phosphine oxide and a transition metal salt. Preferably, the flame retardant is a halogen-free flame retardant.

According to the invention, the phosphine oxide has the structure shown in formula I below:

in the formula I, R₁、R₂And R₃Are the same or different and are each independently selected from C₁-C₁₈Straight chain alkyl radical, C₃-C₁₈Branched alkyl radical, C₁-C₁₈Straight-chain alkoxy radical, C₃-C₁₈Branched alkoxy radical, C₆-C₂₀Substituted or unsubstituted aromatic group, and C₆-C₂₀Substituted or unsubstituted aryloxy.

According to a preferred embodiment of the invention, R₁、R₂And R₃Each independently selected from methyl and ethylAlkyl, propyl, C₄-C₁₈Straight or branched alkyl and C₆-C₂₀Substituted or unsubstituted aromatic group; more preferably selected from C₄-C₁₈Straight or branched alkyl and C₆-C₁₈Substituted or unsubstituted aromatic groups.

According to a more preferred embodiment of the invention, R₁、R₂And R₃Each independently selected from C₄-C₁₈Straight or branched chain alkyl and C having 1 or 2 carbon rings₆-C₁₈An aromatic group.

According to a further preferred embodiment of the invention, R₁、R₂And R₃Each independently selected from C having a main carbon chain of 6 or more carbon atoms₆-C₁₂Straight or branched chain alkyl and substituted or unsubstituted phenyl.

According to the invention, the aromatic group may have a substituent such as a hydroxyl group, a carboxyl group or the like.

According to a further preferred embodiment of the invention, R₁、R₂And R₃Are the same substituents. The phosphine oxide with the structure has stronger complexing ability with transition metal.

According to a preferred embodiment of the present invention, the phosphine oxide is selected from at least one of triphenylphosphine oxide, bis (4-hydroxyphenyl) phenylphosphine oxide, bis (4-carboxyphenyl) phenylphosphine oxide, tributylphosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide and tridecylphosphine oxide, more preferably from at least one of triphenylphosphine oxide, trioctylphosphine oxide, trihexylphosphine oxide and tridecylphosphine oxide.

According to the present invention, the transition metal salt includes a transition metal organic salt and/or a transition metal inorganic salt, preferably at least one of a nitrate, a thiocyanate, a formate, an acetate and an oxalate of a transition metal, more preferably a nitrate. The transition metal is preferably a group VIII metal element, more preferably cobalt and/or nickel. Specifically, the transition metal salt is, for example, at least one selected from the group consisting of cobalt acetate, nickel acetate, cobalt nitrate, nickel thiocyanate, cobalt thiocyanate, nickel nitrate, and cobalt nitrate.

According to a preferred embodiment of the invention, the transition metal salt is cobalt nitrate and/or nickel nitrate. Both of these salts form complexes more readily with phosphine oxides, resulting in higher yields.

According to a preferred embodiment of the present invention, the complex of the phosphine oxide with the transition metal salt has the following structural formula II:

in formula II, M is a transition metal. R₁、R₂And R₃And R in formula I₁、R₂And R₃The same is true.

R₄And R₅Identical or different, each independently selected from formate ions (HCOO)^-) Acetate ion (CH)₃COO^-) Oxalate ion (C)₂O₄H^-) Nitrate ion (NO)₃ ^-) And thiocyanate ion (SCN)^-) At least one of; preferably nitrate ions and thiocyanate ions; nitrate ions are more preferred.

The flame retardant according to the present invention, wherein the preparation step of the complex comprises: stirring and mixing 1-10 parts by weight, preferably 2-5 parts by weight of phosphine oxide and 3-15 parts by weight, preferably 5-10 parts by weight of transition metal salt in an organic solvent, then carrying out microwave heating and supercritical drying to obtain the complex; the organic solvent is preferably at least one of ethanol, acetone, pyridine, tetrahydrofuran, and DMF.

Wherein the stirring speed can be, for example, 90-120rpm, the microwave power is 35-55W, the microwave heating temperature is 35-50 ℃, and the heating time is 3-4.5 hours.

In a preferred embodiment of the invention, the complex obtained after supercritical drying may be denoted as M (CHO)₂)₂(OPR₃)₂Wherein M may be Ni or Co, and R may be phenyl, hexyl, octyl or decyl.

According to the invention, the flame-retardant antistatic polypropylene composition comprises the following components in parts by weight:

according to a preferred embodiment of the present invention, the polypropylene base resin is a narrow molecular weight distribution polypropylene base resin. In some embodiments of the invention, the narrow molecular weight distribution polypropylene base resin has a molecular weight distribution M_w/M_nIs 3.7 to 5.7, preferably 4.0 to 4.5; polymer tailing index PI in molecular weight distribution breadth_HTGreater than 2.3, preferably greater than 2.5. PI (proportional integral)_HTThe high-molecular chain tail end indicates that the polypropylene has more obvious macromolecular chain tail end, and the macromolecular chain tail end can have preferential nucleation in crystallization, so that the crystallization temperature of the polypropylene is increased, the crystallization speed is accelerated, the molding period is favorably shortened, and the molding efficiency is improved; an isotacticity greater than 96%, preferably greater than 97%, more preferably greater than 98%; crystallization temperature T_CGreater than 119 ℃, preferably greater than 121 ℃; the melt index MFR is from 0.01 to 1000g/10min, preferably from 10 to 250g/10min, more preferably from 20 to 60g/10 min.

In propylene polymerization, the molecular weight and melt flow rate of the polymer are usually adjusted by adding a chain transfer agent, which is usually hydrogen. The higher the hydrogen concentration, the lower the molecular weight of the product obtained, and the higher the MFR. At the same time, the chain transfer agent also has an effect on the polymer molecular weight distribution. It has been shown that for some high efficiency polypropylene catalysts, the breadth of the molecular weight distribution of the product is inversely proportional to the hydrogen gas added. Therefore, for the same narrow molecular weight distribution polypropylene, samples with low MFR are more difficult to prepare than samples with high MFR. The invention simultaneously meets the requirements of narrow molecular weight distribution (for example, the molecular weight distribution index is 3.8-4.1) and lower MFR (for example, the MFR is 30-32g/10min) of the polypropylene so as to adapt to the processing and using requirements of materials. The polypropylene base resin with narrow molecular weight distribution not only has narrow molecular weight distribution, but also has higher high molecular tailing index.

The polypropylene base resin with narrow molecular weight distribution does not use peroxide, has low cost and no peculiar smell; higher and adjustable isotacticity, higher melting point and crystallization temperature and higher mechanical strength.

According to some embodiments of the invention, the polypropylene base resin is prepared by a process comprising the steps of:

(1) carrying out prepolymerization reaction on propylene in the presence of a Ziegler-Natta catalyst to obtain a propylene prepolymer;

(2) carrying out propylene polymerization reaction in the presence of the propylene prepolymer obtained in the step (1).

According to a preferred embodiment of the present invention, the step (1) comprises:

in the presence of a Ziegler-Natta catalyst, propylene is subjected to prepolymerization reaction at 0-25 ℃ and 0.1-10.0MPa in a gas phase or a liquid phase to obtain a propylene prepolymer, and the prepolymerization multiple is controlled to be 2-3000 g of polymer/g of catalyst.

In some specific embodiments of the present invention, the reaction temperature in step (1) is preferably 10 to 20 ℃; the prepolymerization pressure is preferably 1.5-3.5 MPa; the prepolymerization reaction is preferably carried out in a liquid phase, and particularly, liquid-phase bulk prepolymerization by adopting propylene can be selected; preferably, the prepolymerization multiple is controlled to be 3 to 2000 g of polymer/g of catalyst; wherein, the pre-polymerization times refer to the weight ratio of the prepolymer to the weight of the originally added catalyst.

According to some embodiments of the invention, the step (2) comprises:

in the presence of the propylene prepolymer obtained in the step (1), carrying out homopolymerization or copolymerization reaction of propylene in gas phase or liquid phase at the temperature of 80-150 ℃, under the pressure of 1-6MPa and under the condition of polymerization reaction time of 0.5-5 hours to obtain the propylene polymer.

In some specific embodiments of the present invention, the polymerization temperature of step (2) is preferably 80 to 100 ℃; the polymerization pressure is preferably 2-5 MPa; the polymerization reaction is preferably carried out in a gas-phase horizontal reaction kettle; the horizontal reaction kettle is provided with a horizontal stirring shaft and adopts quenching liquid for heat removal; the stirring speed in the gas-phase horizontal kettle is 10-150 r/min, and the stirring blade can be one of T-shaped, rectangular, inclined paddle, door-shaped and wedge-shapedOr a plurality thereof; the polymerization reaction time or residence time is preferably controlled to 1 to 3 hours; by molecular weight regulator H₂Controlling the melt flow rate of the polymer; the MFR of the resulting polymer is controlled to be 0.01 to 1000g/10min, preferably 10 to 250g/10min, more preferably 20 to 60g/10 min. And (3) obtaining a polypropylene product with high isotacticity by changing the polymerization temperature control in the step (2), and realizing narrow molecular weight distribution.

According to some preferred embodiments of the present invention, the step (1) and the step (2) may be performed in a batch polymerization operation in one reactor, or may be performed in a continuous polymerization operation in different reactors. In a specific example, said step (1) is carried out continuously in a vertical stirred tank and said step (2) is carried out continuously in a horizontal stirred tank, i.e. the polymerization is carried out continuously in different reactors.

According to some embodiments of the invention, the Ziegler-Natta catalyst may be any of the various Ziegler-Natta catalysts known in the art suitable for use in the preparation of polypropylene. In some specific embodiments, in order to obtain a polypropylene having a narrower molecular weight distribution index and a higher polymer tail index, it is preferred that the Ziegler-Natta catalyst comprises the reaction product of:

(i) a titanium-containing solid catalyst component;

(ii) an alkyl aluminum compound;

(iii) an external electron donor compound.

Wherein the component (i) is a titanium-containing solid catalyst component which is a product of contact reaction of an alkoxy magnesium compound, a titanium compound and an internal electron donor compound.

According to some preferred embodiments of the present invention, the titanium compound is at least one selected from the group consisting of compounds represented by the general formula (III):

Ti(OR)_4-nX_n(III)

r in the general formula (III) is selected from C₁-C₁₄X is a halogen atom, n is an integer selected from 0 to 4; when n is 2 or less, a plurality of R present may be the same or different; the halogen atom may be chlorine, bromine or iodine. In particular, it is suitable forThe titanium compound used in the present invention is selected from at least one of tetraalkoxytitanium, titanium tetrahalide, trihaloalkoxytitanium, dihalodialkoxytitanium and monohalotrialkoxytitanium. More specifically, the titanium tetraalkoxide is at least one selected from the group consisting of titanium tetramethoxide, titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetra-isopropoxide, titanium tetra-n-butoxide, titanium tetra-isobutoxide, titanium tetracyclohexyloxide and titanium tetraphenoxide. The titanium tetrahalide is at least one of titanium tetrachloride, titanium tetrabromide and titanium tetraiodide; the trihaloalkoxy titanium is at least one selected from the group consisting of trichloromethoxy titanium, trichloroethoxy titanium, trichloropropoxy titanium, trichloro-n-butoxy titanium and tribromoethoxy titanium; the dihalo-dialkoxy titanium is selected from at least one of dichloro dimethoxy titanium, dichloro diethoxy titanium, dichloro di-n-propoxy titanium, dichloro diisopropoxy titanium and dibromo diethoxy titanium; the monohalotrialkoxytitanium is selected from at least one of chlorotrimethoxytitanium, chlorotriethoxytitanium, chlorotris-n-propoxytitanium and chlorotriisopropoxytitanium. In some specific embodiments, the titanium compound is preferably a titanium tetrahalide compound, and particularly preferably titanium tetrachloride.

According to some embodiments of the invention, the magnesium alkoxide compound is at least one selected from the group consisting of compounds represented by the general formula (IV):

Mg(OR¹)_2-m(OR²)_m(IV)

r in the general formula (IV)¹And R²Same or different, are respectively selected from C₁-C₈M is more than or equal to 0 and less than or equal to 2. Preferably, R¹And R²Are respectively selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, n-hexyl and (2-ethyl) hexyl; more preferably, R in the formula¹Is ethyl, R²Is a (2-ethyl) hexyl group, 0.001. ltoreq. m.ltoreq.0.5, preferably 0.001. ltoreq. m.ltoreq.0.25, more preferably 0.001. ltoreq. m.ltoreq.0.1. It is to be noted that the magnesium alkoxide represented by the general formula (II) merely represents the compositional content, i.e., the molar ratio, of each alkoxy group, and does not completely represent the specific structure of the magnesium alkoxide. In particular, for example Mg (OEt) (OiPr) (in which Et represents ethyl and iPr represents ethyl)Table i-propyl) only indicates that the molar ratio of ethoxy groups to i-propoxy groups in the magnesium alkoxide compound is 1, and it may be a mixture of diethoxymagnesium and di-iso-propoxymagnesium, or an ethoxy i-propoxymagnesium compound, or a mixture of the three, that is, a mixture of magnesium alkoxide compounds having a plurality of structures and a total molar ratio of ethoxy groups to i-propoxy groups of 1.

The magnesium alkoxide compound is spherical-like in appearance, and has an average particle diameter (D50) of 10 to 150 μm, preferably 15 to 100 μm, and more preferably 18 to 80 μm. The particle size distribution index SPAN is less than 1.1, the preferable particle size distribution index SPAN is less than 1.05, wherein the calculation formula of SPAN is shown in formula (III):

SPAN＝(D90-D10)/D50 (V)

in formula (V), D90 represents a particle size corresponding to a cumulative weight fraction of 90%, D10 represents a particle size corresponding to a cumulative weight fraction of 10%, and D50 represents a particle size corresponding to a cumulative weight fraction of 50%.

According to some preferred embodiments of the present invention, the titanium-containing solid catalyst component may further contain a trace amount of magnesium halide (e.g., MgI)₂And/or MgCl₂) Or an alcoholate thereof, but the content of the magnesium alkoxide compound of formula (V) should be higher than 90% by weight, preferably higher than 95% by weight, more preferably higher than 98% by weight, based on the total weight of the magnesium alkoxide compound of formula (IV) and the magnesium halide.

The alkoxy magnesium compound suitable for use in the present invention may be obtained commercially or may be prepared according to a conventional method. For example, the alkoxy magnesium compound may be composed of metal magnesium, alcohol (R) corresponding to alkoxy¹OH and/or R²OH) and a mixed halogenating agent under an inert atmosphere. Wherein the mixed halogenating agent is a mixture of a halogen and a halogen compound. The halogen may be one or more of iodine, bromine and chlorine. Non-limiting examples of the halogen compounds are: magnesium chloride, magnesium bromide, magnesium iodide, potassium chloride, potassium bromide, potassium iodide, calcium chloride, calcium bromide, calcium iodide, mercuric chloride, mercuric bromide, mercuric iodide, ethoxymagnesium iodide, methoxymagnesium iodide, isopropylmagnesium iodideOne or more of magnesium, hydrogen chloride and chloroacetyl chloride. The mixed halogenating agent is particularly preferably a mixture of iodine and magnesium chloride, and more preferably, the weight ratio of iodine to magnesium chloride is 1 (0.02 to 20), more preferably 1 (0.1 to 10).

According to some embodiments of the present invention, in the above-mentioned preparation process of the magnesium alkoxide compound, the molar ratio of the magnesium metal to the total halogen atoms in the mixed halogenating agent may be, for example, 1 (0.0002 to 0.2), preferably 1 (0.001 to 0.08). The weight ratio of the alcohol corresponding to the alkoxy group to the metal magnesium may be, for example, (4-50):1, preferably (6-25): 1. R¹OH and R²The molar ratio Y of OH is 3(2-g)/g>Y>(2-g)/g, wherein 0. ltoreq. g.ltoreq.2, preferably 0.001. ltoreq. g.ltoreq.0.5, more preferably 0.001. ltoreq. g.ltoreq.0.25, still more preferably 0.001. ltoreq. g.ltoreq.0.1.

According to some preferred embodiments of the present invention, the temperature of the reaction may be, for example, 30 to 90 ℃, preferably 30 to 80 ℃, and more preferably 50 to 75 ℃ during the preparation of the above-mentioned magnesium alkoxide compound. In actual practice, it is possible to judge whether the reaction is finished by observing the cessation of the discharge of hydrogen produced by the reaction.

The shape of the magnesium metal is not particularly limited in the present invention, and may be, for example, a granular shape, a ribbon shape, or a powdery shape. In order to keep the average particle diameter of the resulting magnesium alkoxide compound within a suitable range and to obtain a good particle morphology, the magnesium metal is preferably spherical magnesium metal having an average particle diameter of 10 to 360 μm, more preferably 50 to 300. mu.m. In the present invention, the surface of the metallic magnesium is not particularly limited, but if a coating such as a hydroxide is formed on the surface of the metallic magnesium, the reaction is slowed down. Preferably, therefore, the total content of active magnesium in the magnesium metal is >95 wt.%, more preferably >98 wt.%.

In the present invention, the water content in the alcohol corresponding to the alkoxy group in the process of producing the above-mentioned magnesium alkoxide compound is not particularly limited, and in order to obtain a magnesium alkoxide compound having more excellent performance, it is required that the water content is as small as possible. It is generally necessary to control the water content in the alcohol corresponding to the alkoxy group to 1000pm or less, preferably 200ppm or less.

According to some embodiments of the invention, the inert atmosphere is well known to the person skilled in the art, preferably a nitrogen and/or argon atmosphere. Furthermore, the preparation of the magnesium alkoxide compounds is generally carried out in an inert solvent as reaction medium. Wherein the inert solvent may be C₆-C₁₀Preferably at least one of hexane, heptane, octane, decane, benzene, toluene, xylene and derivatives thereof.

According to some preferred embodiments of the present invention, in the preparation process of the magnesium alkoxide compound, the magnesium metal, the alcohol corresponding to the alkoxy group, the mixed halogenating agent, and the inert solvent may be introduced at once or may be introduced in portions. The divided charging of the raw materials prevents instantaneous generation of a large amount of hydrogen gas and prevents the generation of droplets of the alcohol or the halogenating agent due to the instantaneous generation of a large amount of hydrogen gas, and such a charging method is preferable from the viewpoint of safety and reaction uniformity. The number of times of the divided charging can be determined according to the scale of the reactor and the amount of each material. After the reaction is completed, the obtained final product dialkoxy magnesium can be stored in a dry state or suspended in an inert diluent used for preparing the titanium-containing catalyst solid component in the next step.

According to some embodiments of the present invention, the internal electron donor compounds include alkyl esters of aliphatic and aromatic monocarboxylic acids, alkyl esters of aliphatic and aromatic polycarboxylic acids, aliphatic ethers, cycloaliphatic ethers, and aliphatic ketones; preferably selected from C₁-C₄Alkyl esters of saturated aliphatic carboxylic acids, C₇-C₈Alkyl esters of aromatic carboxylic acids, C₂-C₆Fatty ethers, C₃-C₄Cyclic ether, C₃-C₆Saturated aliphatic ketones and 1, 3-diether compounds.

In some specific embodiments, the internal electron donor compound is preferably a phthalate compound represented by formula (VI),

in the formula (VI), R⁴And R⁵Same or different is C₂-C₈Straight chain alkyl, C₃-C₁₀Branched alkyl radical, C₅-C₁₀Cycloalkyl radical, C₆-C₁₅Aryl, or C₇-C₁₅Alkaryl or aralkyl. Preferably, R⁴And R⁵Is C₃-C₈Straight chain alkyl, C₃-C₁₀Branched alkyl radical, C₆-C₁₀Aryl, or C₇-C₁₀Alkaryl or aralkyl. R⁶-R⁹Same or different, is hydrogen, halogen, C₁-C₆Straight chain alkyl, C₃-C₁₀Branched alkyl radical, C₅-C₁₀Cycloalkyl radical, C₆-C₂₀Aryl, or C₇-C₂₀An alkaryl group or an aralkyl group, and the hydrogen on the carbon of the alkyl, aryl, alkaryl, or aralkyl group may be optionally substituted with an alkane or halogen atom. Preferably, R⁶-R⁹Same or different, is hydrogen, halogen, C₁-C₆Straight chain alkyl, C₃-C₈A branched alkyl group, and the hydrogen on the alkyl carbon may be optionally substituted with an alkane or a halogen atom.

According to some embodiments of the present invention, the phthalate-based compound suitable for use in the present invention is selected from the group consisting of dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di-n-pentyl phthalate, diisopentyl phthalate, di-n-hexyl phthalate, diisohexyl phthalate, di-n-octyl phthalate, diisooctyl phthalate, dibenzyl phthalate, tetramethyl dimethyl phthalate, tetramethyl diethyl phthalate, di-n-propyl tetramethyl phthalate, diisopropyl tetramethyl phthalate, di-n-butyl tetramethyl phthalate, diisobutyl tetramethyl phthalate, di-n-pentyl tetramethyl phthalate, diisopentyl phthalate, di-n-pentyl tetramethyl phthalate, di-n-pentyl phthalate, di-n-pentyl phthalate, di-hexyl phthalate, di-n-pentyl phthalate, di, At least one member selected from the group consisting of di-n-hexyl tetramethylphthalate, di-isohexyl tetramethylphthalate, di-n-octyl tetramethylphthalate, di-isooctyl tetramethylphthalate, di-benzyl tetramethylphthalate, dimethyl tetrabromophthalate, diethyl tetrabromophthalate, di-n-propyl tetrabromophthalate, diisopropyl tetrabromophthalate, di-n-butyl tetrabromophthalate, diisobutyl tetrabromophthalate, di-n-pentyl tetrabromophthalate, di-isoamyl tetrabromophthalate, di-n-hexyl tetrabromophthalate, di-isohexyl tetrabromophthalate, di-n-octyl tetrabromophthalate, di-isooctyl tetrabromophthalate and di-benzyl tetrabromophthalate.

According to some preferred embodiments of the present invention, during the preparation of the titanium-containing solid catalyst component, the molar ratio of titanium in the titanium compound to magnesium in the magnesium alkoxide compound may be (0.5-100): 1; preferably (1-50): 1. The molar ratio of the internal electron donor compound to magnesium in the magnesium alkoxide compound may be (0.005-10):1, preferably (0.01-1): 1.

According to some embodiments of the present invention, the titanium-containing solid catalyst component is generally prepared using an inert solvent as the reaction medium. Wherein the inert solvent may be selected from C₆-C₁₀At least one of an alkane or an arene. Preferably hexane, heptane, octane, decane, benzene, toluene, and at least one of xylene or its derivatives, most preferably toluene. The molar ratio of the inert solvent to magnesium in the magnesium alkoxide compound may be (0.5-100):1, preferably (1-50): 1.

According to some preferred embodiments of the present invention, the order of adding the magnesium alkoxide compound, the titanium compound, the internal electron donor compound, and the inert solvent during the preparation of the titanium-containing solid catalyst component is not particularly limited. For example, the above components may be mixed uniformly in the presence of an inert solvent, or the components may be diluted with an inert solvent in advance and then the respective solutions may be mixed uniformly. The number of mixing is not particularly limited, and the mixing may be performed once or in a plurality of times. Specifically, the titanium-containing solid catalyst component can be prepared according to the following methods:

the method comprises the following steps:

(1) preparing an alkoxy magnesium carrier compound, an internal electron donor and an inert solvent into a suspension, then reacting the suspension with a mixture formed by a part of titanium compound and the inert solvent, and filtering to obtain a solid product;

(2) adding the obtained solid product into the mixture of the other part of the titanium compound and the inert solvent for continuous reaction, and filtering to obtain a solid product;

(3) repeating the reaction of the step 2 for 2-4 times;

(4) washing the solid product with inert solvent to obtain the titanium-containing solid catalyst component.

In the steps (1) to (3), the amount of the titanium compound to be added in each case may be appropriately selected depending on the number of times of repeating the reaction, and for example, may be 1/n, where n is the number of times of repeating the step 2 + 2.

The second method comprises the following steps:

(1) preparing an alkoxy magnesium carrier compound, a part of internal electron donor and an inert solvent into a suspension, then reacting the suspension with a mixture formed by a part of titanium compound and the inert solvent, and filtering to obtain a solid product;

(2) adding the obtained solid product into a mixture formed by another part of titanium compound, inert solvent and the rest part of internal electron donor to continue reacting, and filtering to obtain a solid product;

(3) continuously adding the obtained solid product into a part of mixture of the titanium compound and the inert solvent for continuous reaction, and filtering to obtain a solid product;

(4) repeating the reaction of the step 3 for 2-4 times;

(5) washing the solid product obtained in the last time by using an inert solvent to obtain the titanium-containing solid catalyst component.

In the steps (1) to (4), the amount of the titanium compound to be added at each time can be appropriately selected depending on the number of times of repeating the reaction, and for example, may be 1/n, where n is the number of times of repeating the 3 rd step + 3.

The third method comprises the following steps:

(1) preparing an alkoxy magnesium carrier compound and an inert solvent into a suspension, then reacting with a mixture formed by a part of titanium compound and the inert solvent, adding an internal electron donor compound, continuing to react, and filtering to obtain a solid product;

(2) adding the obtained solid product into a mixture formed by another part of titanium compound and inert solvent for continuous reaction, and filtering to obtain a solid product;

(3) repeating the reaction of the step 2 for 2-4 times;

In the steps (1) to (3), the amount of the titanium compound to be added at each time can be appropriately selected depending on the number of times of repeating the reaction, and for example, may be 1/n, where n is the number of times of repeating the 2 nd step + 2.

The method four comprises the following steps:

(1) preparing an alkoxy magnesium carrier compound, a part of internal electron donor and an inert solvent into a suspension, then reacting the suspension with a mixture formed by a part of titanium compound and the inert solvent, adding the rest part of internal electron donor compound, continuing to react, and filtering to obtain a solid product;

(2) adding the obtained solid product into a mixture formed by another part of titanium compound and an inert solvent for continuous reaction, and filtering to obtain a solid product;

(3) repeating the reaction of the step 2 for 2-4 times;

According to some embodiments of the present invention, the inert solvent for washing is preferably hexane during the preparation of the solid catalyst component. In the present invention, the method of washing is not particularly limited, and it is preferably performed by decantation, filtration or the like. The amount of the inert solvent to be used, the washing time and the number of washing times are not particularly limited, and for example, the amount of the inert solvent to be used for washing may be 1 to 1000 moles, preferably 10 to 500 moles, based on 1 mole of magnesium in the above-mentioned magnesium alkoxide compound. The washing time may be, for example, 1 to 24 hours, preferably 6 to 10 hours. Further, the washing is preferably performed under agitation conditions from the viewpoint of washing uniformity and washing efficiency.

According to a preferred embodiment of the present invention, in the preparation of the titanium-containing solid catalyst component, the conditions for contacting and reacting the magnesium alkoxide compound, the titanium compound, the internal electron donor compound and the inert solvent generally comprise: the reaction temperature may be-40 ℃ to 200 ℃, preferably-20 ℃ to 150 ℃; the reaction time may be 1 minute to 20 hours, preferably 5 minutes to 8 hours.

According to some embodiments of the invention, said component (ii) comprises an alkylaluminum compound of formula (VII),

AlR¹⁰ _pX_3-p(VII)

in the formula (VII), R¹⁰Is hydrogen or a hydrocarbon group with 1-20 carbon atoms, X is halogen, and p is an integer of 1-3; specifically, the aluminum compound can be at least one selected from triethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-octylaluminum, diethylaluminum monohydrogen, diisobutylaluminum monohydrogen, diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum sesquichloride and ethylaluminum dichloride, and preferably triethylaluminum and/or triisobutylaluminum.

According to a preferred embodiment of the present invention, said component (iii) comprises an aminosilane of general formula (VIII),

Si(OR₁)₃(NR₂R₃)(VIII)

in the formula (VIII), R₁Is a hydrocarbon group having 1 to 6 carbon atoms, preferably a hydrocarbon group having 2 to 6 carbon atoms. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl and the like, and ethyl is particularly preferable. R₂Is a hydrocarbon group having 1 to 12 carbon atoms or hydrogen. Specific examples thereof include hydrogen and methylEthyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl, octyl and the like, with ethyl being particularly preferred. R₃Is a hydrocarbon group having 1 to 12 carbon atoms. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl and octyl, with ethyl being particularly preferred. The compound represented by the formula (VIII) is preferably at least one of dimethylamino triethoxysilane, diethylamino trimethoxysilane, diethylamino tri-n-propoxysilane, di-n-propylaminotriethoxysilane, methyl-n-propylaminotriethoxysilane, tert-butylaminotriethoxysilane, ethyl-n-propylaminotriethoxysilane, ethyl-isopropylaminotriethoxysilane, and methyl-ethylaminotriethoxysilane. These organosilicon compounds may be used alone, or 2 or more of these organosilicon compounds may be used in combination.

According to some embodiments of the invention, the method of synthesizing the compound represented by formula (VIII) is: the compound of formula (VIII) is synthesized by reacting an alkylamine with a Grignard reagent in an equivalent ratio to obtain a magnesium salt or a lithium salt of the alkylamine through a Grignard exchange reaction, and then continuing the equivalent reaction of the magnesium salt or the lithium salt of the alkylamine with tetraethoxysilane.

According to some preferred embodiments of the present invention, the compound represented by the general formula (VIII), in addition to the synthesis using the Grignard reagent described above, can be synthesized by reacting an alkoxy halosilane represented by the general formula (IX) with a dialkylamine represented by the general formula (X),

X_nSi(OR₁)₄-q(IX)

NHR₂R₃(X)

in the alkoxy halosilane represented by the formula (IX), X is a halogen, and examples thereof include fluorine, chlorine, bromine and the like, and chlorine is particularly preferred; r₁Examples of the hydrocarbon group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group (e.g., n-propyl group, isopropyl group), a butyl group (e.g., n-butyl group, isobutyl group, tert-butyl group, etc.), and particularly preferably an ethyl groupAnd (4) a base. In formula (IX), q is 1,2 or 3, and is particularly preferably 1. Specific examples of the alkoxyhalosilane represented by the formula (IX) include triethoxyfluorosilane, triethoxychlorosilane, trimethoxychlorosilane, tri-n-propoxychlorosilane, triethoxybromosilane and the like, and triethoxychlorosilane is particularly preferable.

In the formula (X), R₂Is a hydrocarbon group having 1 to 12 carbon atoms or hydrogen. Specific examples thereof include hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl, and octyl, with ethyl being particularly preferred. R₃Is a hydrocarbon group having 1 to 12 carbon atoms. Specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl and octyl, with ethyl being particularly preferred. The dialkylamine represented by the formula (X) includes dimethylamine, diethylamine, di-n-propylamine, methyl-n-propylamine, tert-butylamine, ethyl-n-propylamine, ethyl-isopropylamine, methylethylamine, and the like.

According to some embodiments of the invention, the alkyl aluminum compound may be used in amounts conventional in the art. Generally, the molar ratio of the aluminum in the aluminum alkyl compound to the titanium in the solid component of the catalyst is (20-500):1, preferably (50-500):1, more preferably (25-100): 1.

According to some preferred embodiments of the present invention, there is no particular limitation on the amount of the external electron donor used. Preferably, the molar ratio between the aluminium in the aluminium alkyl compound and the silicon of the external electron donor compound is (0.1-500):1, preferably (0.2-200):1, more preferably (1-100): 1.

According to some embodiments of the present invention, it is preferred to use an aminosilane external electron donor and polymerize the aminosilane at a relatively high temperature of 80-100 ℃ to obtain a propylene polymer with a narrow molecular weight distribution. The polymer has the characteristics of high and adjustable isotacticity, narrow molecular weight distribution and high trailing index of high molecules. The polypropylene has high melting point and crystallization temperature and high mechanical strength.

The narrow molecular weight distribution polypropylene prepared and used in the present invention is described in chinese patent application No. 201510418659.3 entitled "a narrow molecular weight distribution polypropylene and method of making the same," which is incorporated herein by reference in its entirety.

According to some embodiments of the present invention, the carbon nanofiber antistatic agent contains 1 to 5wt% of transition metal, preferably 2 to 4 wt% of transition metal. This portion of the transition metal may come from the catalyst used in the carbon nanofiber preparation process. As one advantage of the present invention, the carbon nanofibers used are directly used to prepare the flame retardant antistatic composition without removing the transition metal catalyst therefrom. Due to the existence of transition metal and other potential reasons, the carbon nanofiber used in the invention can generate synergistic effect with the flame retardant, and is beneficial to generating a compact carbon layer for blocking flame and materials, so that the addition amount of the flame retardant can be reduced, and the carbon nanofiber and the flame retardant are compounded without mutually negative influence to cause the reduction of performances of each other.

The invention has no special requirements on the purity, the length-diameter ratio, the diameter and the appearance of the carbon nano fiber.

According to some embodiments of the present invention, a method of preparing a carbon nanofiber suitable for use in the present invention comprises: the carbon source is subjected to acid treatment, then a complex is formed with the transition metal catalyst, and the complex (i.e., the complex formed by the carbon source and the transition metal catalyst) is subjected to carbonization treatment.

The following are exemplary methods of making carbon nanofibers:

1) the carbon source is pretreated by a mixed acid treatment method or a grinding treatment method of phosphoric acid, nitric acid and hydrochloric acid (volume ratio is 1:1:1) to obtain a pretreated substance.

Wherein the carbon source is a condensed carbon source and can be at least one of carbon asphalt, petroleum asphalt, coal pitch, coal tar, natural graphite, artificial graphite, bamboo charcoal, carbon black, activated carbon and graphene; here, the carbon source having a carbon content of 80wt% or more is preferable, and for example, at least one of coal pitch, petroleum pitch and bamboo charcoal having a carbon content of 80wt% or more is preferable.

2) Compounding: and compounding the pretreatment substance with a metal catalyst to obtain a compound.

The metal catalyst is preferably at least one of a sulfate, nitrate, acetate and cyclopentadienyl compound of a transition metal, preferably a group VIII metal element, such as Fe, Co or Ni, and may also be Cr.

Preferably, the mass percentage of the transition metal catalyst to the carbon source is (35-70) to 100 in terms of transition metal.

The metal catalyst is preferably cobalt nitrate and/or nickel nitrate here, considering that the nitrogen element contained in the catalyst may contribute to the synergistic effect to promote the flame-retardant effect.

3) And (3) carbonization treatment: and (3) carrying out carbonization reaction on the composite at the temperature of 800-1200 ℃ under the protection of high-purity nitrogen, keeping the temperature for 0.5-5 hours, and cooling to room temperature to obtain the self-assembled carbon fiber. The temperature of the carbonization treatment is preferably 950 ℃ or 1150 ℃, and the isothermal reaction is carried out for 1.5 to 2.5 hours. No post-treatment is needed to remove the metal impurities.

Compared with the commonly used short-acting antistatic agent in the prior art, such as a high molecular polymer antistatic agent, the carbon nanofiber used in the invention is a long-acting antistatic agent and can provide a long-acting antistatic effect.

According to some preferred embodiments of the present invention, the flame retardant antistatic polypropylene composition further comprises an inorganic flame retardant component, preferably the inorganic flame retardant component is selected from group IIA and IIIA metal hydroxides, more preferably from magnesium hydroxide and/or aluminium hydroxide. The flame retardant effect can be further enhanced by adding the inorganic flame retardant component.

According to a preferred embodiment of the invention, the weight ratio of the complex to the inorganic flame retardant component is (1-5):1, preferably (2.5-3.5): 1.

The flame retardant may be prepared by first preparing the complex and then physically mixing the complex with the inorganic flame retardant components. The physical mixing here may be ball milling, mechanical stirring. Preferably, the homogenization is carried out by mechanical stirring, with a stirring speed of about 10 rpm.

The flame retardant provided by the invention is particularly suitable for preparation of polypropylene fibers and non-woven fabrics, and can form a synergistic promotion effect with an antistatic agent, so that polypropylene products meet the requirements of environmental protection and safety, and the flame retardant efficiency is improved.

According to some embodiments of the present invention, the polypropylene and/or elastomer is preferably present in an amount of 12 to 18 parts by weight.

According to some preferred embodiments of the invention, the polymeric material comprises an olefin polymer and/or an elastomeric rubber.

According to some embodiments of the invention, the olefin polymer comprises ethylene propylene co-polypropylene and/or polyethylene. The polyethylene comprises low density polyethylene and/or high density polyethylene. In some specific embodiments, the low density polyethylene is preferably a copolymerized linear low density polyethylene of ethylene and an alpha-olefin.

According to some embodiments of the invention, the alpha-olefin comprises propylene, 1-butene, 2-butene, 3-methyl-1-butene, 4-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3-dimethyl-1-pentene, 3, 4-dimethyl-1-pentene, 4-dimethyl-1-pentene, 1-hexene, 4-methyl-1-hexene, 5-methyl-1-hexene, 1-heptene, 2-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-decene, 4-methyl-1-pentene, 4-dimethyl-1-pentene, at least one of 1-hexadecene, 1-octadecene and 1-eicosene, more preferably at least one of 1-butene, 1-hexene and 1-octene.

According to some preferred embodiments of the present invention, the elastomer rubber comprises one or more of a thermoplastic elastomer TPE, a thermoplastic polyurethane elastomer TPU and a polyolefin elastomer POE.

According to some embodiments of the invention, the slip agent is preferably present in an amount of 0.022 to 0.15 parts by weight, more preferably 0.03 to 0.125 parts by weight, and most preferably 0.04 to 0.08 parts by weight.

According to some preferred embodiments of the invention, the slip agent is preferably a fast dusting slip agent.

According to some embodiments of the invention, the slip agent comprises a hydrocarbon having one or more functional groups in the molecule selected from the group consisting of hydroxyl, aryl, substituted aryl, halogen, alkoxy, ester, unsaturated carbon, acrylate, carboxyl, sulfate, and phosphate.

According to some preferred embodiments of the invention, the slip agent comprises an aliphatic or aromatic hydrocarbon derivative, preferably a fatty acid metal salt.

According to some embodiments of the invention, the slip agent comprises a fatty acid or a metal salt of an inorganic acid having 7 to 26 carbon atoms, preferably 10 to 22 carbon atoms.

In some specific embodiments, examples of fatty acids suitable for use in the present invention include, but are not limited to, monocarboxylic acids lauric acid, stearic acid, succinic acid, stearoyl lactic acid, phthalic acid, benzoic acid, hydroxystearic acid, ricinoleic acid, naphthenic acid, oleic acid, palmitic acid, and erucic acid. Examples of inorganic acids suitable for use in the present invention include, but are not limited to, sulfuric acid and phosphoric acid. Metals suitable for use in the present invention include, but are not limited to, lithium, sodium, magnesium, calcium, strontium, barium, zinc, cadmium, aluminum, tin, and lead.

In some specific embodiments, examples of fatty acid metal salts suitable for use in the present invention include, but are not limited to, magnesium stearate, calcium stearate, sodium stearate, zinc stearate, calcium oleate, magnesium oleate.

According to a preferred embodiment of the present invention, the flame retardant antistatic polypropylene composition is preferably used in an amount of 82 to 88 parts by weight. In some embodiments, the flame retardant antistatic polypropylene composition is used in an amount of 85 parts by weight.

The second aspect of the invention provides a flame-retardant antistatic polypropylene fiber, which is prepared by a spun-bond spinning method of the flame-retardant antistatic polypropylene fiber composition according to the first aspect of the invention. Wherein the fibers have a diameter of 0.1 to 50 denier.

The third aspect of the present invention provides a flame-retardant antistatic polypropylene nonwoven fabric made of the fiber according to the second aspect of the present invention.

The flame retardant antistatic polypropylene nonwoven fabric of the present invention may comprise monocomponent and/or bicomponent fibers. "bicomponent fiber" refers to a fiber having two or more distinct polymeric regions. Bicomponent fibers are also known as conjugate or multicomponent fibers. The polymers are typically different from each other, although two or more components may comprise the same polymer. These polymers are distributed in substantially distinct zones across the cross-section of the bicomponent fiber and generally extend continuously along the length of the bicomponent fiber. The construction of a bicomponent fiber can be, for example, a sheath/core distribution (in which one polymer is surrounded by another), a side-by-side, a sandwich, or an "islands-in-the-sea" distribution. In the sheath-core bicomponent fiber, the flame retardant antistatic polypropylene fiber composition of the present invention preferably constitutes the core layer. The skin layer may advantageously be composed of polyethylene homopolymers and/or copolymers, including linear low density polyethylene and substantially linear low density polyethylene.

The flame-retardant antistatic polypropylene nonwoven fabric of the present invention may be composed of continuous or discontinuous fibers (e.g., short fibers). The fibers of the present invention are very useful for making nonwoven fabrics. The nonwoven material of the invention preferably has a weight of 0.015 to 0.25kg/m²The unit area is heavy. In particular, the nonwoven material preferably has a weight of 0.015 to 0.03kg/m²Is heavy per unit area. Since a narrow molecular weight distribution polypropylene is used and the nonwoven has an average filament denier of 0.05 to 8, a reduction in average filament denier allows for the production of a softer nonwoven. For example, the nonwoven has greater softness when the filament denier reaches 0.05 to 1 denier.

The fibers used in the present invention, particularly spunbond fibers, can be microfibers or, more specifically, they can be fibers having an average diameter of about 15 to 30 microns and having a denier of about l.5 to 3.0, which are closely arranged in the range of deniers used to produce a nonwoven fabric that meets the requirements of a nonwoven fabric for a mask having a filtration rate of from 90 or greater as required by NIOSH.

Further, it is to be understood that the fibers may be used in any other fibrous applications known in the art, such as binder fibers and carpet fibers, in addition to the nonwoven materials described above. For sheath-core fibers used in binder fibers, the flame retardant antistatic polypropylene fiber compositions of the present invention may advantageously constitute sheath layers with the core layer being polyethylene (including high density polyethylene and linear low density polyethylene), polypropylene (including homopolymers or random copolymers, preferably containing no more than about 3% ethylene by weight of the random copolymer), or a polyester, such as polyethylene terephthalate (PET).

The term "base resin" as used herein refers to the neat resin, i.e., the resin that does not form the composition.

The term "halogen-free" as used herein means that the compound or mixture or composition is free of halogens.

The term "nonwoven fabric" as used herein refers to a fabric formed without the need to spin a woven fabric, but is formed by orienting or randomly arranging textile staple fibers or filaments to form a web structure, which is then consolidated by mechanical, thermal or chemical means. The preparation method of the non-woven fabric mainly comprises the following steps: air laying, melt blowing, spunbonding, and carding.

The term "microfibers" as used herein refers to small diameter fibers having an average diameter of no greater than 100 microns.

The term "spunbond fibers" as used herein refers to small diameter fibers formed by: molten thermoplastic material is extruded as filaments from a plurality of fine, usually annular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly attenuated by drawing.

The term "optionally" as used herein means either with or without, and with or without the addition of.

The manner of mixing the compositions disclosed in the present invention includes mixing the components by a high speed mixer and then melt mixing, or by pre-melt mixing in a separate extruder (e.g., single screw technology machine, twin screw extruder, multi screw extruder, buss kneader) or in a dual reactor.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention takes polypropylene with narrow molecular weight distribution as a raw material, and the non-woven fabric prepared from the fibers obtained by a spun-bonded spinning method can be widely applied to the fields of medicine and health (medical masks and surgical gowns), labor protection and personal protection (dust masks), personal sanitary products (sanitary towels, diapers and cotton wet tissues) and the like.

(2) The polypropylene non-woven fabric prepared by the invention is of a non-crosslinked structure, can be recycled according to common polypropylene modified materials, does not cause secondary pollution, and meets the requirement of circular economy.

(3) After the narrow molecular weight distribution polypropylene is used, the torque of the spun-bonded extrusion mechanism is obviously reduced, the stability of the pressure of a spinning nozzle can be improved, and the fineness and the uniformity of the spun-bonded filaments are ensured.

(4) The polypropylene with narrow molecular weight distribution prepared by hydrogen telomerization has lower content of Volatile Organic Compounds (VOC) relative to the product obtained by a degradation method, and is nontoxic, harmless and odorless when being prepared into non-woven fabrics for personal protective articles such as masks and the like.

Detailed Description

The invention will be described in further detail with reference to the following examples, but it should be noted that: the present invention is by no means limited to these examples.

The relevant data in the examples of the present invention were obtained according to the following test methods:

(1) molecular weight distribution breadth index Mw/Mn, peak position molecular weight Mp, weight average molecular weight Mw, and Z average molecular weight Mz: the measurement was carried out by using a gel permeation chromatograph manufactured by Polymer Laboratories, UK, model number PL-GPC220, in combination with an IR5 type infrared detector, wherein the gel chromatograph had 3 tandem Plgel10 μm MIXED-B columns, the solvent and mobile phase were 1,2, 4-trichlorobenzene (containing 0.3g/1000mL of antioxidant 2, 6-di-t-butyl-p-cresol), the column temperature was 150 ℃ and the flow rate was 1.0mL/min, and the calibration was carried out universally using EasiCal PS-1 narrow distribution polystyrene standards manufactured by PL.

(2) Polymer tailing index PI in molecular weight distribution breadth_HT: the peak molecular weight Mp, the weight average molecular weight Mw and the Z average molecular weight Mz measured by the above method (1) are calculated in g/mol according to the following formulae:

PI_HT＝10⁵x (Mz/Mp)/Mw (formula 1)

(3) And (3) isotacticity: measured according to the method described in the national standard GB/T2412.

(4) Crystallization temperature T_C: the instrument was calibrated with indium and zinc metal standards using a DIAMOND type DSC from PE, with a sample mass of about 5mg, a nitrogen atmosphere, and a gas flow of 20 mL/min. Heating the antioxidant-containing aggregate sample to be tested to 210 ℃ at the speed of 10 ℃/min, keeping the temperature for 5min to eliminate the thermal history, then cooling to 50 ℃ at the cooling rate of 10 ℃/min, recording a crystallization heat release curve, and recording the temperature corresponding to the peak value of the crystallization heat release curve as the crystallization temperature T_C。

(5) Melt flow rate MFR: measured according to ISO1133, 230 ℃ under a load of 2.16 kg.

(6) The titanium atom content in the titanium-containing solid catalyst component and the Ziegler-Natta catalyst was measured using a 721 spectrophotometer, available from the institute of safety and technology development, Inc.

(7) The particle size and particle size distribution of the magnesium alkoxide and the catalyst were measured by a Malvern Mastersizer TM2000 laser particle sizer with n-hexane as the dispersant (SPAN ═ D90-D10)/D50).

(8) Determination of the m value in the magnesium alkoxide Compound: 0.1 g of an alkoxy magnesium compound was added to 10mL of a 1.2mol/L hydrochloric acid aqueous solution, and the mixture was decomposed by shaking for 24 hours, and ethanol and 2-ethylhexanol were measured by a gas chromatograph (available from Allen analytical instruments, Ltd., type GC-7960), and then the value of m was calculated according to the following formula:

wherein w1 is the mass of 2-ethylhexanol, and w2 is the mass of ethanol.

(9) The content of internal electron donor in the Ziegler-Natta catalyst is determined by Waters 600E liquid chromatography or gas chromatography.

(10) Heat distortion temperature HDT: measured according to ASTM D648. A455 kPa load was placed on the center of a 127X 13X 3mm standard test piece, and the temperature was raised at 2 ℃/min until the deformation became 0.25 mm.

(11) Flexural modulus and flexural strength of polypropylene: measured according to ASTM D790-97, GB/T9341-2008 standard.

(12) Tensile strength of polypropylene: measured according to ASTM D638-00, GB/T1040.2-2006.

(13) Izod notched impact Strength (IZOD 23/-20 ℃ C.): measured according to ASTM D256-00, GB/T1843-2008 standard.

(14) Flexural rigidity test of nonwoven fabrics, ASTM D5732-95:

samples for flexural rigidity were obtained by cutting a 1 inch long by 6 inch long strip from the center of the cloth, with the long axis of the strip aligned parallel to the Machine Direction (MD) of the cloth. MD is defined as the direction of the cloth parallel to the collector motion or conveyor motion during cloth formation. For each sample, the basis weight (in grams per square meter) was determined by dividing the sample weight measured with an analytical balance (model BSA223S-CW, sydows, in square meters of area). The bending stiffness (G) of the cloth samples was measured according to ASTM D5732-95. C was calculated using the following formula 2.

G＝9.8m*C³10^-3(mN. cm) (formula 2)

Where G is the average flexural stiffness per unit width in millinewton centimeters of the test piece (test piece), m is the sample basis weight measured in grams per square meter, and C is the bend length in centimeters. For all measurements, the indicator was inclined at 41.50 ° from the horizontal.

(15) Tensile strength test of nonwoven fabric ASTM D4595-11:

a2.5 cm wide by 15cm long strip was cut from the center of the web in the Machine Direction (MD) to obtain a sample for nonwoven fabric measurement. Basis weight in grams per square meter for each sample. The sample was then loaded parallel to the crosshead displacement MD into an Instron5967 equipped with a 100N sensor (calibrated and balanced) and a pneumatic line contact jig (flat end jig face rubberized) with an initial spacing of 2.5 inches. This was done by first inserting the sample into the upper clamp and snapping the upper clamp to grip 3cm from the narrow edge of the sample. The measurement of elongation at break was done using a contact extensometer. The sample was pulled at a speed of 0.5cm/s to break. Load and elongation (0.5% strain increase) were recorded per 0.25mm of displacement. The strain was calculated by removing the clamp position by 5cm and multiplying by 100. The reduced load (gf/gsm/2.5cm width) was calculated by dividing the force measured in grams (gf) by the basis weight of the 2.5cm wide sample described above.

(16) And (3) oxygen index test: the test was carried out according to the method described in the national Standard GB/T5454-1997.

(17) And (3) surface resistivity test: the test was performed according to GB/T1410-2006.

Preparation of polypropylene base resin HPP

1. Preparation of Polypropylene base resin HPP101

1) Raw materials

Preparation of the main catalyst: A16L pressure-resistant reactor equipped with a stirrer was sufficiently replaced with nitrogen, then 10L of ethanol, 300mL of 2-ethylhexanol, 11.2g of iodine, 8g of magnesium chloride and 640g of magnesium powder were added to the reactor and mixed well with stirring, and the system was heated to 75 ℃ with stirring and refluxed until no more hydrogen was discharged. The reaction was stopped, washed with 3L of ethanol, filtered and dried to obtain the dialkoxy magnesium support. Its D50 value was 30.2 μm, SPAN 0.81, and m 0.015. 650g of the dialkoxymagnesium support, 3250mL of toluene, and 65mL of di-n-butyl phthalate (DNBP) were weighed and prepared into a suspension. Adding 2600mL of toluene and 3900mL of titanium tetrachloride into a 16L pressure-resistant reaction kettle repeatedly replaced by high-purity nitrogen, heating to 80 ℃, adding the prepared suspension into the kettle, keeping the temperature for 1 hour, adding 65mL of di-n-butyl phthalate (DNBP), slowly heating to 110 ℃, keeping the temperature for 2 hours, and performing pressure filtration to obtain a solid matter. The resulting solid was added with a mixture of toluene 5070mL and titanium tetrachloride 3380mL, and then stirred at 110 ℃ for 1 hour, and thus treated 3 times. And (3) performing filter pressing, washing the obtained solid with hexane for 4 times, wherein the dosage of the solid is 600mL each time, and performing filter pressing and drying to obtain the solid component of the main catalyst. The solid component of the obtained catalyst had a titanium atom content of 2.4% by weight and a di-n-butyl phthalate (DNBP) content of 9.5% by weight.

Triethyl aluminum was used as cocatalyst during the polymerization; diethylaminotriethoxysilane (DAMTS) as external electron donor; propylene and hydrogen are in polymerization grade and are used after water and oxygen are removed; the hexane was used after dehydration.

2) Testing device

The device adopts a continuous kettle type prepolymerization and horizontal kettle gas-phase series polymerization process. The prepolymerization reactor is a vertical stirring kettle with a jacket for cooling, the volume is 5 liters, the stirring blade is a turbine inclined slurry, and the stirring speed is 500 revolutions per minute; the horizontal gas phase reactor is a horizontal stirring kettle with the volume of 0.2 cubic meter, the stirring paddle is a T-shaped inclined paddle blade, the inclination angle is 10 degrees, and the stirring speed is 100 revolutions per minute.

3) Test conditions

The first step of prepolymerization: the reaction pressure is 2.39MPa, the reaction temperature is 15 ℃, and the reaction time is 15 minutes; the feeding amounts of the main catalyst, triethyl aluminum and diethylamino triethoxysilane (DAMTS) were 1.3g/hr, 0.067mol/hr and 0.0058mol/hr, respectively; the molar ratio of Al to Si is 8.59; the propylene feed rate was 15 kg/hr.

The second step of gas-phase polymerization: the homopolymerization temperature is 85 ℃, the reaction pressure is 2.35MPa, and the reaction time is 85 minutes; the feed amount of propylene was 10 kg/hr; the hydrogen/propylene molar ratio in the reaction gas phase was 0.013.

4) Analysis of Polymer Properties

A48-hour continuous test was carried out under the above conditions, the apparatus was operated stably, and the polymer obtained by the reaction was subjected to analytical tests, the results of which are shown in Table 1.

2. Preparation of Polypropylene base resin HPP102

1) Starting material (as in example 1);

2) test apparatus (same as example 1);

3) test conditions

The first step of prepolymerization: the reaction pressure is 2.39MPa, the reaction temperature is 15 ℃, and the reaction time is 15 minutes; the feeding amounts of the main catalyst, triethyl aluminum and diethylamino triethoxysilane (DAMTS) are respectively 0.75g/hr, 0.043mol/hr and 0.0044 mol/hr; the molar ratio of Al to Si is 7.16; the propylene feed rate was 15 kg/hr.

The second step of gas-phase polymerization: the homopolymerization temperature is 95 ℃, the reaction pressure is 2.35MPa, and the reaction time is 85 minutes; the feed amount of propylene was 10 kg/hr; the hydrogen/propylene molar ratio in the reaction gas phase was 0.006.

4) Test results

3. Preparation of Polypropylene base resin HPP103

1) Starting material (as in example 1);

2) test apparatus (same as example 1);

3) test conditions

The second step of gas-phase polymerization: the homopolymerization temperature is 100 ℃, the reaction pressure is 2.35MPa, and the reaction time is 85 minutes; the feed amount of propylene was 10 kg/hr; the hydrogen/propylene molar ratio in the reaction gas phase was 0.006.

4) Test results

4. Preparation of Polypropylene base resin HPP104

1) Raw materials

Triethyl aluminum was used as cocatalyst during the polymerization; dicyclopentyldimethoxysilane (DCPDMS) was used as external donor; propylene and hydrogen are in polymerization grade and are used after water and oxygen are removed; the hexane was used after dehydration.

2) Test device (same as example 1)

3) Test conditions

The first step of prepolymerization: the reaction pressure is 2.44MPa, the reaction temperature is 10 ℃, and the reaction time is 15 minutes; the feeding amounts of the main catalyst, the triethyl aluminum and the dicyclopentyl dimethoxy silane (DCPDMS) are respectively 0.87g/hr, 0.047mol/hr and 0.0079 mol/hr; the molar ratio of Al to Si is 6.11; the propylene feed rate was 15 kg/hr.

The second step of gas-phase polymerization: the homopolymerization temperature is 85 ℃, the reaction pressure is 2.4MPa, and the reaction time is 90 minutes; the feed amount of propylene was 10 kg/hr; the hydrogen/propylene molar ratio in the reaction gas phase was 0.03.

4) Test results

5. Preparation of Polypropylene base resin HPP105

1) Raw materials (same as comparative example 2);

2) test apparatus (same as example 1);

3) test conditions

The first step of prepolymerization: the reaction pressure is 2.34MPa, the reaction temperature is 10 ℃, and the reaction time is 15 minutes; the feeding amounts of the main catalyst, the triethyl aluminum and the dicyclopentyl dimethoxy silane (DCPDMS) are respectively 0.6g/hr, 0.047mol/hr and 0.0079 mol/hr; the molar ratio of Al to Si is 6.11; the propylene feed rate was 15 kg/hr.

Gas phase polymerization in step (2): the homopolymerization temperature is 66 ℃, the reaction pressure is 2.3MPa, and the reaction time is 90 minutes; the feed amount of propylene was 10 kg/hr; the hydrogen/propylene molar ratio in the reaction gas phase was 0.05.

4) Test results

6. Preparation of Polypropylene base resin HPP106

1) Raw materials: the same procedure as in example 1 was repeated except that no electron donor was used;

2) test apparatus (same as example 1);

3) test conditions

The first step of prepolymerization: the reaction pressure is 2.5MPa, the reaction temperature is 15 ℃, and the reaction time is 15 minutes; the feeding amounts of the main catalyst and the triethyl aluminum are respectively 0.4g/hr and 0.058 mol/hr; the propylene feed rate was 10 kg/hr.

The second step of gas-phase polymerization: the homopolymerization temperature is 91 ℃, the reaction pressure is 2.3MPa, and the reaction time is 60 minutes; the feed amount of propylene was 10 kg/hr; the hydrogen/propylene molar ratio in the reaction gas phase was 0.008.

Examples

Example 1

1. Preparation of flame-retardant antistatic polypropylene fiber composition

The raw material ratios and reaction conditions of the flame retardant and the polypropylene composition prepared in this example are shown in tables 2 and 3. Wherein the flame retardant component A is phosphine oxide, the flame retardant component B is transition metal salt, and the flame retardant component C is an inorganic flame retardant component.

1) Preparation of (halogen-free) flame retardants

Adding triphenylphosphine oxide and cobalt nitrate into ethanol, stirring at the speed of 100rpm, and heating the mixed material with microwave under stirring at the heating power of 50W and the temperature of 40 ℃ for 4 h. Subjecting the material after microwave heating reaction to supercritical drying to obtain triphenylphosphine oxide and cobalt nitrateFormed complex Co (OPPh)₃)₂(NO₃)₂。

The complex Co (OPPh) prepared above is added₃)₂(NO₃)₂And mechanically stirring and homogenizing the mixture with magnesium hydroxide at the stirring speed of 10rpm to obtain the flame retardant.

2) Preparation of carbon nanofiber antistatic agent

Coal tar pitch with the carbon content of 85 wt% is used as a carbon source, and grinding pretreatment is carried out by using mixed acid of phosphoric acid/nitric acid/hydrochloric acid (volume ratio is 1:1:1) to obtain a pretreatment product.

And adding the pretreated substance and a catalyst cobalt nitrate into a ball mill for mixing to obtain a compound.

And (3) carrying out carbonization reaction on the compound under the protection of high-purity nitrogen at 950 ℃, keeping the temperature for 1.5 hours, and then cooling to room temperature to obtain the self-assembled carbon nanofiber. The metallic impurities of the catalyst are removed without post-treatment, and the cobalt content is 2wt percent through determination.

3) Preparation of (halogen-free) flame-retardant antistatic polypropylene composition

HPP101, the carbon nanofiber antistatic agent prepared above, the foam cell nucleating agent zinc borate, the antioxidant 1010(BASF company) and the antioxidant 168(BASF company) are added into a high-speed stirrer together with the flame retardant prepared above and are uniformly mixed. Then the mixed material is added into a feeder of a double-screw extruder manufactured by Keplon company, the material enters into the double screws through the feeder, and the temperature of the screws is kept between 170 ℃ and 200 ℃ in the processing process. And melting and mixing uniformly by a screw, and entering a Labline100 microparticle preparation system, wherein the torque is controlled to be about 65% and the rotating speed is 300 rpm. Obtaining the flame-retardant antistatic polypropylene composition microparticles.

4) Preparation of (halogen-free) flame-retardant antistatic polypropylene fiber composition

95 parts of the flame-retardant antistatic polypropylene composition, 5 parts of general LDPE and 0.05 part of slipping agent oleamide. After mixing by a high-speed mixer, the mixture was blended by a buss kneader, and the temperature of the die of the extruder was 195 ℃.

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Lefenhausen Reicofil 4 Spunbond/Meltblown apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS, and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.75ghm total output, using spunbond technology to produce a cloth at 15gsm at a line speed of 150 meters/minute, the resulting fiber had 3dpf, and the embossing calender roll and smooth roll were the same oil temperature. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Example 2

1. Preparation of flame-retardant antistatic polypropylene fiber composition

1) The preparation methods of the flame retardant, the carbon nanofiber antistatic agent, and the flame retardant antistatic polypropylene composition were the same as in example 1, except for the raw material formulations and reaction conditions shown in tables 2 and 3. For example, the example uses HPP102, and the formed halogen-free flame retardant is Ni (OPOt) which is a complex formed by trioctylphosphine oxide and nickel nitrate₃)₂(NO₃)₂And the prepared carbon nanofiber antistatic agent contains 3 wt% of nickel.

2) Preparation of flame-retardant antistatic polypropylene fiber composition

90 parts by weight of the flame-retardant antistatic polypropylene composition, 10 parts by weight of general LDPE and 0.06 part by weight of slipping agent oleamide. After mixing by a high-speed mixer, the mixture was blended by a buss kneader, and the temperature of the die of the extruder was 195 ℃.

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Laifenhouse Reicofil 4 Spunbond/Meltblown composite apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.8ghm total output, making the fabric at a line speed of 165 meters/minute at 15gsm, resulting in a fiber with 3dpf, and the same oil temperature for the embossing calender roll and the smoothing roll. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Example 3

1. Preparation of flame-retardant antistatic polypropylene fiber composition

1) The preparation methods of the flame retardant, the carbon nanofiber antistatic agent, and the flame retardant antistatic polypropylene composition were the same as in example 1, except for the raw material formulations and reaction conditions shown in tables 2 and 3. For example, the example uses HPP103, and the formed halogen-free flame retardant is Co (OPOt) complex formed by trioctylphosphine oxide and cobalt nitrate₃)₂(NO₃)₂And the prepared carbon nanofiber antistatic agent contains 3 wt% of cobalt.

2) Preparation of flame-retardant antistatic polypropylene fiber composition

85 parts of the flame-retardant antistatic polypropylene composition, 15 parts of general LDPE and 0.04 part of slipping agent oleamide. After mixing by a high-speed mixer, the mixture was blended by a buss kneader, and the temperature of the die of the extruder was 200 ℃.

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Laifenhouse Reicofil 4 Spunbond/Meltblown composite apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.65ghm total output to produce a cloth at 18gsm at a line speed of 145 m/min, the fiber had 2dpf, and the embossing calender roll and smooth roll were the same oil temperature. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Example 4

1. Preparation of flame-retardant antistatic polypropylene fiber composition

1) Preparation of flame-retardant antistatic composition

The preparation method of the flame-retardant antistatic polypropylene composition is the same as that in example 1, except that the carbon nanofiber antistatic agent is replaced by carbon black in the preparation of the flame-retardant antistatic polypropylene composition.

2) Preparation of flame-retardant antistatic polypropylene fiber composition

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Laifenhouse Reicofil 4 Spunbond/Meltblown composite apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.65ghm total output, making a cloth at 18gsm at a line speed of 145 m/min, the fiber had 7dpf, and the embossing calender roll and smooth roll were the same oil temperature. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Example 5

1. The flame retardant antistatic polypropylene fiber composition was prepared as in example 1 except for the formulation of the flame retardant antistatic polypropylene composition in Table 2 and the temperature and pressure conditions of the calender rolls in Table 3. For example, magnesium hydroxide is not included in the flame retardant antistatic polypropylene composition.

2. The flame-retardant antistatic polypropylene nonwoven fabric was prepared as in example 1.

Example 6

1. The flame retardant antistatic polypropylene fiber composition was prepared as in example 1 except for the formulation of the flame retardant antistatic polypropylene composition in Table 2. For example, HPP101 in the flame retardant antistatic polypropylene composition is replaced with HPP 104.

Example 7

1. The flame retardant antistatic polypropylene fiber composition was prepared as in example 1 except for the formulation of the flame retardant antistatic polypropylene composition in Table 2 and the temperature and pressure conditions of the calender rolls in Table 3. For example, HPP101 in the flame retardant antistatic polypropylene composition was replaced with HPP 105.

Example 8

1. The flame retardant antistatic polypropylene fiber composition was prepared as in example 1 except for the formulation of the flame retardant antistatic polypropylene composition in Table 2 and the temperature and pressure conditions of the calender rolls in Table 3. For example, HPP101 in the flame retardant antistatic polypropylene composition was replaced with HPP 106.

Comparative example 1

1. Preparation of flame-retardant antistatic polypropylene fiber composition

1) The preparation method of the carbon nanofiber antistatic agent and the flame-retardant antistatic polypropylene composition is the same as that of example 1, except that the flame retardant is replaced by red phosphorus.

2) Preparation of flame-retardant antistatic polypropylene fiber composition

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Laifenhouse Reicofil 4 Spunbond/Meltblown composite apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.75ghm total output, making a cloth at 15gsm at a line speed of 150 meters/minute, the fiber had 8dpf, and the embossing calender roll and smooth roll were the same oil temperature. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Comparative example 2

1. Preparation of flame-retardant antistatic polypropylene fiber composition

1) The carbon nanofiber antistatic, flame retardant antistatic polypropylene composition was prepared in the same manner as in example 1, except that the flame retardant was replaced with a composition of hexabromocyclododecane and antimony trioxide (weight ratio about 2.5:1) for testing.

2) Preparation of flame-retardant antistatic polypropylene fiber composition

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Lefenhausen Reicofil 4 Spunbond/meltblow composite apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.8ghm total output, making the fabric at a line speed of 165 meters/minute at 15gsm, resulting in a fiber with 8dpf, and the same oil temperature for the embossing calender roll and the smoothing roll. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Comparative example 3

1. Preparation of flame-retardant antistatic polypropylene fiber composition

1) The preparation method of the flame-retardant antistatic polypropylene composition is the same as that of example 1, except that only magnesium hydroxide is used instead of the flame retardant in the preparation of the flame-retardant antistatic polypropylene composition.

2) Preparation of flame-retardant antistatic polypropylene fiber composition

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Laifenhouse Reicofil 4 Spunbond/Meltblown composite apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.65ghm total output, making a cloth at 18gsm at a line speed of 145 m/min, the fiber had 10dpf, and the embossing calender roll and smooth roll were the same oil temperature. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Comparative example 4

1. Preparation of flame-retardant antistatic polypropylene fiber composition

1) The preparation methods of the flame retardant, the carbon nanofiber antistatic agent, and the flame retardant antistatic polypropylene composition were the same as in example 1, except for the raw material formulations and reaction conditions shown in tables 2 and 3. For example, this example utilizes a commercially available high flow, narrow molecular weight distribution polypropylene product, designated H30S, prepared by the Zhenhai chemical company using peroxide degradation.

2) Preparation of flame-retardant antistatic polypropylene fiber composition

2. Preparation of flame-retardant antistatic polypropylene non-woven fabric

The tests were carried out using a German Lefenhausen Reicofil 4 Spunbond/meltblow composite apparatus. For this line, four extruders run to a spinneret set (composite-fiber configuration). The operation of the production line may be single wire (S) and double wire (SS) and triple wire (SSs) and quadruple wire (SSSs). In addition, SMS, SMMS, SSMMS and ssmmmss can also be combined with meltblown spunbond. These four extruders have different outputs and also pass through four spinning pumps with different outputs. For this test, the output of each spinning pump was equal and the throughput was 0.65ghm total output, making a cloth at 18gsm at a line speed of 145 m/min, the fiber had 20dpf, and the embossing calender roll and smooth roll were the same oil temperature. The temperature and pressure conditions of the calender rolls are shown in Table 3. Here, dpf represents the denier per filament, i.e., denier per filament, ghm represents grams of polymer per minute per hole, and gsm represents grams per square meter.

Comparative example 5

1. The flame retardant antistatic polypropylene fiber composition was prepared as in example 1 except for the formulation of the flame retardant antistatic polypropylene composition in Table 2 and the temperature and pressure conditions of the calender rolls in Table 3. For example, the flame retardant in the flame retardant antistatic polypropylene composition is triphenylphosphine oxide alone.

Comparative example 6

1. The flame retardant antistatic polypropylene fiber composition was prepared as in example 1 except for the formulation of the flame retardant antistatic polypropylene composition in Table 2. For example, the flame retardant in the flame retardant antistatic polypropylene composition is cobalt nitrate alone.

TABLE 1 Synthesis conditions and Properties of Polypropylene base resins

As can be seen from the data in table 1:

(1) the polypropylene with narrow molecular weight distribution prepared by the invention has high isotacticity, and the reaction conditions can be adjusted according to requirements to obtain polypropylene with different isotacticity. The polypropylene has a low melting point, excellent rigidity and a higher heat distortion temperature, and can be used for sealing materials.

(2) The molecular weight distribution index represented by the ratio of the weight average molecular weight to the number average molecular weight of the polymer product HPP105 obtained by conventional 66 ℃ polymerization is relatively large, namely the molecular weight distribution is relatively wide. Compared with the HPP105, the HPPs 101, 102 and 103 in the narrow molecular weight distribution polypropylene have narrow molecular weight distribution and higher mechanical strength.

(3) Diethylamino triethoxysilane (DAMTS) is used as an external electron donor (HPP101-HPP103), and the isotacticity of the polymer is relatively high. Compared with HPP104 and HPP105 which use conventional external electron donors, the polypropylene of the invention has narrower molecular weight distribution; and the hydrogen regulation sensitivity of the catalyst is also better. In addition, HPP105 (polymerization temperature 66 ℃ C.) had a broader molecular weight distribution and lower isotacticity than HPP104 (polymerization temperature 85 ℃ C.).

(4) Comparing HPPs 101-103 with HPP106, it can be seen that: after the external electron donor is added, the isotacticity of the polymer is obviously improved, and the polypropylene has narrower molecular weight distribution.

(5) Compared with HR30, the narrow molecular weight distribution polypropylene HPP101-HPP103 of the present invention has molecular weight distribution width exceeding the level of narrow molecular weight distribution in degradation method and high molecular tail index PI_HTAnd crystallization temperature are both significantly higher than for the degraded narrow distribution polypropylene. PI (proportional integral)_HTHigher indicates more pronounced macromolecular chain tails in the polypropylene, which are able to nucleate preferentially in crystallization. Therefore, compared with the degradation method, the preparation method of the polypropylene with narrow molecular weight distribution has shorter molding period and higher molding efficiency, namely the direct polymerization method of the invention is more economical, environment-friendly and efficient.

Table 2 shows that the nonwoven fabric provided by the invention has excellent mechanical property, flame retardant property and antistatic property, wherein oxygen meansThe number is up to 31, the material can be used in the field with higher requirement on flame retardant level, and the surface resistivity reaches 10⁹Omega antistatic grade. The oxygen index of the non-woven fabric and the relevant flame retardant test conditions show that the flame retardant and the antistatic agent can exert a synergistic effect.

As can be seen from the data in Table 3, the nonwoven fabrics prepared from the polypropylene base resins obtained in examples 1-8 have good mechanical properties, especially the tensile strength in both MD and TD directions is higher than that of the nonwoven fabric obtained from the conventional polypropylene HR30, the tensile strength in both MD and TD directions is similar, the nonwoven fabrics used in the mask and the air purifier filter element have good durability, and the permeability of PM2.5 is significantly lower than that of the nonwoven fabrics prepared from the polypropylene used in comparative examples 1-6.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.

Claims

1. A flame-retardant antistatic polypropylene fiber composition comprises the following components in parts by weight:

75-95 parts of flame-retardant antistatic polypropylene composition;

5-25 parts of polyolefin and/or elastomer;

0.01-0.25 part of slipping agent;

wherein the flame retardant antistatic polypropylene composition comprises a flame retardant comprising a complex of a phosphine oxide and a transition metal salt;

the phosphine oxide has the structure shown in formula I:

formula I

2. The fiber composition according to claim 1, wherein the flame retardant antistatic polypropylene composition is 80-90 parts by weight.

3. The fiber composition of claim 1, wherein the polyolefin and/or elastomer is present in an amount of 10 to 20 parts by weight.

4. The fiber composition of claim 1, wherein the slip agent is present in an amount of 0.02 to 0.2 parts by weight.

5. The fiber composition of claim 1, wherein R is₁、R₂And R₃Each independently selected from C₄-C₁₈Straight or branched chain alkyl and C having 1 or 2 carbon rings₆-C₁₈An aromatic group.

6. The fiber composition of claim 1, wherein R is₁、R₂And R₃Each independently selected from C having a main carbon chain of 6 or more carbon atoms₆-C₁₂Straight or branched chain alkyl and substituted or unsubstituted phenyl.

7. The fiber composition of claim 1, wherein the phosphine oxide comprises at least one of triphenylphosphine oxide, bis (4-hydroxyphenyl) phenylphosphine oxide, bis (4-carboxyphenyl) phenylphosphine oxide, tributylphosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide, tridecylphosphine oxide, tributyl phosphate, and dibutyl butylphosphate.

8. A fiber composition according to claim 1, wherein the transition metal salt comprises an organic transition metal salt and/or an inorganic transition metal salt.

9. The fiber composition of claim 8, wherein the transition metal salt comprises at least one of a nitrate, thiocyanate, formate, acetate, and oxalate salt of a transition metal.

10. The fiber composition of claim 8, wherein the transition metal is a group VIII metal element.

11. A fibre composition according to claim 10, wherein the transition metal is cobalt and/or nickel.

12. The fiber composition according to claim 1, wherein the flame retardant antistatic polypropylene composition comprises in parts by weight:

100 parts of polypropylene base resin;

5-50 parts of a flame retardant;

0.1-10 parts of carbon nanofiber antistatic agent; and optionally

And 0.5 part or less of antioxidant.

13. The fiber composition of claim 12, wherein the flame retardant is present in an amount of 10 to 20 parts by weight.

14. The fiber composition of claim 12, wherein the carbon nanofiber antistatic agent is present in an amount of 1 to 3 parts by weight.

15. The fiber composition of claim 12, wherein the antioxidant is present in an amount of 0.1 to 0.3 parts by weight.

16. The fiber composition of claim 12, wherein the carbon nanofiber antistatic agent comprises 1 to 5wt% of a transition metal.

17. The fiber composition of claim 12, wherein the carbon nanofiber antistatic agent is prepared by a method comprising:

the carbon source is treated by acid, then the carbon source and the transition metal catalyst form a compound, and the compound is carbonized at the temperature of 800-1200 ℃ under the protection of inert gas.

18. The fiber composition of claim 17, wherein the carbon source is selected from at least one of carbon pitch, petroleum pitch, coal tar, natural graphite, artificial graphite, bamboo charcoal, carbon black, activated carbon, and graphene.

19. The fiber composition of claim 17, wherein the carbon source is at least one selected from the group consisting of coal pitch, petroleum pitch, and bamboo charcoal having a carbon content of 80wt% or more.

20. A fiber composition according to claim 17, wherein the transition metal catalyst is selected from at least one of a sulfate, a nitrate, an acetate, and a cyclopentadienyl compound of a transition metal.

21. A fibrous composition according to claim 20, wherein the transition metal is selected from at least one of iron, cobalt, nickel and chromium.

22. The fiber composition of claim 17, wherein the mass ratio of the transition metal catalyst to the carbon source, calculated as transition metal, is (35-70): 100.

23. The fibrous composition according to any of claims 1 to 22, wherein the flame retardant further comprises an inorganic flame retardant component selected from group IIA and IIIA metal hydroxides, and/or the weight ratio of the complex to the inorganic flame retardant component in the flame retardant is (1-5): 1.

24. A fibrous composition according to claim 23, wherein the inorganic flame retardant component is selected from magnesium hydroxide and/or aluminium hydroxide.

25. A fibrous composition according to any of claims 1 to 22, characterized in that said polyolefin comprises ethylene propylene co-polypropylene and/or polyethylene; and/or the elastomer comprises at least one of a thermoplastic elastomer TPE, a thermoplastic polyurethane elastomer TPU and a polyolefin elastomer POE.

26. A fibrous composition according to claim 25, wherein the polyethylene comprises low density polyethylene and/or high density polyethylene.

27. A fibrous composition according to claim 26, wherein the low density polyethylene is a copolymeric linear low density polyethylene of ethylene and an alpha-olefin.

28. The fibrous composition of claim 27, wherein the alpha-olefin comprises propylene, 1-butene, 2-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3-dimethyl-1-pentene, 3, 4-dimethyl-1-pentene, 4-dimethyl-1-pentene, 1-hexene, 4-methyl-1-hexene, 5-methyl-1-hexene, 1-heptene, 2-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, or mixtures thereof, At least one of 1-octadecene and 1-eicosene.

29. The fiber composition of claim 28, wherein the alpha-olefin comprises at least one of 1-butene, 1-hexene, and 1-octene.

30. Fiber composition according to any of claims 1 to 22, wherein the slip agent is present in an amount of 0.022 to 0.15 parts by weight.

31. The fiber composition of any of claims 1-22, wherein the slip agent comprises one or more functional groups in the molecule selected from the group consisting of hydroxyl, aryl, substituted aryl, halogen, alkoxy, ester, unsaturated carbon, acrylate, carboxyl, sulfate, and phosphate.

32. The fiber composition of claim 30, wherein the slip agent is present in an amount of 0.03 to 0.125 parts by weight.

33. The fiber composition of claim 30, wherein the slip agent is present in an amount of 0.04 to 0.08 parts by weight.

34. A fibrous composition according to any of claims 1 to 22, characterized in that the slip agent comprises an aliphatic or aromatic metal salt.

35. The fibrous composition according to any of claims 1 to 22, wherein the slip agent comprises C₇-C₂₆Fatty acid metal salt, C₇-C₂₆Metal sulfate and C₇-C₂₆At least one of metal phosphates.

36. The fibrous composition of claim 35, wherein the slip agent comprises C₁₀-C₂₂Fatty acid metal salt, C₁₀-C₂₂Metal sulfate and C₁₀-C₂₂At least one of metal phosphates; and/or the metal comprises at least one of lithium, sodium, magnesium, calcium, strontium, barium, zinc, cadmium, aluminum, tin, and lead.

37. The fiber composition of claim 35, wherein the fatty acid comprises at least one of lauric acid, stearic acid, oleic acid, palmitic acid, and erucic acid;

and/or the fatty acid metal salt comprises at least one of magnesium stearate, calcium stearate, sodium stearate, zinc stearate, calcium oleate, and magnesium oleate.

38. A flame retardant antistatic polypropylene fiber, which is prepared by a spunbond spinning method using the flame retardant antistatic polypropylene fiber composition as defined in any one of claims 1 to 37, wherein the diameter of the fiber is 0.1 to 50 denier.

39. A flame retardant antistatic polypropylene nonwoven fabric made from the fiber of claim 38.