FIELD OF THE INVENTION

The present invention relates to a masterbatch for fiber application, a dope containing the masterbatch, and a process for preparing fibers from the dope. In particular, the present invention relates to a masterbatch, a dope containing the masterbatch, and a process for preparing island fibers using the masterbatch, such as for preparing PA/PE island fiber.

BACKGROUND OF THE INVENTION

Fiber is a widely used material in various field of the world. Island fibers, such as PA/PE island fibers, are developing new materials for various applications. Carbon black is a commonly used material to colour up the fibers, especially island fibers. Generally, in such a practice, a carbon black masterbatch is first formed, and then the carbon black masterbatch is added to a dope for a fiber. Generally, the concentration of carbon black in the carbon black masterbatch is about 30% by weight, based on the total weight of the carbon black masterbatch. The amount of the carbon black masterbatch added to a dope for an island fiber is determined according to practical requirements. Usually it is desirable that more than about 20% by weight of such carbon black masterbatch is in a dope, based on the weight of the dope, to make the island fiber looks dark or even black. That is, generally, for this, more than about 6% by weight of carbon black is required to be present in the dope.

However, because of the poor dispersibility of the carbon black in a dope for a fiber, especially island fiber, currently a carbon black masterbatch having 30% by weight of carbon black generally can only be added to the dope in an amount of below 1.5% by weight, based on the weight of the dope, especially in a dope for an island fiber, such as PA PE island fiber. When the amount is greater than 1.5% by weight, a process for preparing a fiber will be broken down because of spinneret plate jam or the obtained filament will be broken. Such an unstable process is not desirable in the art. For a long time people seek for a technical solution to improve the amount of the carbon black in a dope for fiber, especially for island fiber to get fibers with dark and uniform color, at the same time maintain the desired strength of the obtained fiber.

DIC Corporation, Japan, provides carbon black masterbatchs for island fiber application, such as a carbon black masterbatch commercially available therefrom with the trade type of BK-35. With these carbon black masterbatchs, the dispersibility of the carbon black in a dope is improved by modifying the carbon black in terms of dispersibility during the production of the carbon black. DIC Corporation provides a carbon black with very special and high dispersion performance to make the obtained carbon black masterbatch applicable for dark island fiber. However the carbon black provided by DIC needs an additional processing step during the production of the carbon black to improve the dispersibility of the carbon black in a dope, thus the producing process thereof will be costly and complicated. Also the quality stability of the obtained carbon black from batch to batch of the process is poor. In the art, people still need a carbon black masterbatch that provides improved content of carbon black to a dope for fiber application, especially for island fiber, such that fibers that have darker and more uniform color as compared with those in the prior art will be obtained, and at the same time the stable good qualities, such as the desired strength, of the obtained fiber are maintained, and the cost for producing the carbon black masterbatch is reduced.

SUMMARY

To remove the deficiencies in the prior art, the present invention provides a new carbon black masterbatch to a dope for fiber application, such as for island fiber application, especially for PA/PE island fiber application; and provides a new process using the same for making fibers, such as island fibers, especially PA/PE island fibers. Compared with the prior art, the carbon black masterbatch of the invention can be produced at low cost and has stable quality.

In the present invention, commercially available common carbon black may be used for the carbon black masterbatch of the invention, without the need of pretreating the carbon black to improve the dispersibility thereof before producing the carbon black masterbatch.

With the carbon black masterbatch of the invention, the amount of the carbon black in a dope for a fiber application is increased, and the fiber obtained from the invention has darker and more uniform color as compared with the prior art. At the same time the stable good qualities, such as the desired strength, of the obtained fiber are maintained.

During the manufacturing of a fiber, such as an island fiber, the carbon black masterbatch of the invention is added to a dope of a fiber to color up the dope, such that the obtained fiber will be dark. In addition to the improved dark color and its uniformity, the flowability of the carbon black masterbatch of the invention is improved and whereby the flowability of the dope is improved when the dope is extruded through the spinneret, thus no spinneret plate jam will occur and almost no broken filament will appear.

DESCRIPTION ABOUT THE FIGURE

Figure 1 is a chart showing comparing data on the shear viscosity of the inventive carbon black masterbatchs and comparative carbon black masterbatch.

DETAILED DESCRIPTION OF THE INVENTION

Generally, the present invention relates to a new carbon black masterbatch in a dope for fiber application, such as for island fiber application, especially for PA/PE island fiber application, and a new process using the same for making fibers, such as for island fiber application, especially for PA/PE island fiber application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Expressions "a", "an", "the", when used to define a term, include both the plural and singular forms of the term.

In the present invention, the term "dope" means a material that is directed to a spinneret for spinning fibers.

The term "polymer", as used herein, includes both homopolymers, that is, polymers prepared from a single reactive compound, and copolymers, that is, polymers prepared by reaction of at least two polymer forming reactive, monomeric compounds.

In the present invention, when used, the expressions "Nylon", "polyamide", and "PA" are used interchangeable.

Though polyamide will also be a thermoplastic polymer, the term "thermoplastic polymer", when used herein, does not equal to the polyamide mentioned in the invention. The term "thermoplastic polymer" in present invention is used independently and separately from the term "polyamide".

The term "(meth)acrylate" includes both "acrylate" and "methacrylate".

The term "miscible" refers to a homogeneous mixture of two polymers, that is a mixture when solidified that is lacking in identifiable regions or occlusions of one polymer in the other polymer.

In a first aspect of the invention, the present invention relates to a carbon black masterbatch for making a fiber, especially an island fiber, comprising:

(a) a polyamide,

(b) carbon black, and

(c) a polymer of vinyl aromatic monomers.

Component (a) of the carbon black masterbatch is a polyamide. Generally, any type of polyamide useful for forming fibers may be suitable as component (a), such as aliphatic and aromatic polyamides, for example polyamides obtained by condensing an aliphatic or aromatic dicarboxylic acid having 4 to 12 carbon atoms and an aliphatic or aromatic diamine having 2 to 12 carbon atoms. The polyamide suitable for the carbon black masterbatch of the invention may be obtained by any polymerization process known to a skilled person in the art. For example, polyamide may be produced by the process disclosed in CN 1259533 A (herein incorporated by reference in entirety).

Aliphatic dicarboxylic acids suitable for use in the synthesis of polyamides for use herein includes, but not limit to, adipic acid, pimelic acid, azelaic acid, suberic acid, sebacic acid and dodecane dioic acid. Aromatic dicarboxylic acids include, but not limit to: phthalic acid, isophthalic acid, terephthalic acid, and naphthalene dicarboxylic acid.

Representative aliphatic diamines include, by way of example, alkylenediamines, such as hexamethylenediamine and octamethylenediamine. Suitable aromatic diamines for example are the following: diaminobenzenes, such as 1,4-diaminobenzene, 1,3-diaminobenzene, and 1 ,2-diaminobenzene; diaminotoluenes, such as 2,4-diaminotoluene, 2,3-diaminotoluene, 2,5-diaminotoluene, and 2,6-diaminotoluene; ortho-, meta-, and para-xylene diamines; ortho-, meta-, and para-2,2'-diaminodiethyl benzene; 4,4'-diaminobiphenyl; 4,4'-diaminodiphenyl methane; 4,4'-diaminodiphenyl ether; 4,4'-diaminodiphenyl thioether; 4,4'-diaminodiphenyl ketone; and 4,4'-diaminodiphenyl sulfone.

Mixtures of the foregoing aliphatic and aromatic dicarboxylic acids and diamines may be used as well. It is also possible to produce the polyamide from acid derivatives and amine derivatives, such as an acid chloride and an amine salt, as well as by self-condensation of a lactam or a ω-aminocarboxylic acid. Examples of such lactams include ε-caprolactam and ω-laurolactam. Examples of such ω-amino acids include 11-aminoundecanoic acid, 12-aminododecanoic acid, 4-aminophenylcarboxyl methane, l-(4-aminophenyl)-2-carboxyl ethane,

3-(4-aminophenyl)-l-carboxyl propane, para-(3-amino-3'-hydroxy)dipropyl benzene, and the like.

The aromatic polyamides include, but not limit to, polyxyleneadipamide; polyhexamethyleneterephthalamide; polyphenylenephthalamide; polyxyleneadipamide/hexamethyleneadipamide; polyesteramide elastomer; polyetheramide elastomer; polyetheresteramide elastomer; and dimeric acid copolymerized amide.

The aliphatic polyamides suitable for present invention include, but not limit to: polycapro lactam (PA-6); poly(hexamethylene adipamide) (PA-6,6): PA-3,4; PA-4; PA-4,6; PA-5,10; PA-6; PA-6,6; PA-6,9; PA-6, 10; PA-6,12; PA-11; and PA-12. Preferred polyamides are the aliphatic polyamides, especially PA 6 or PA 6,6, most preferably PA6.

Component (b) of the carbon black masterbatch of the invention is carbon black. In the present invention, there is no specific requirement on the carbon black per se. Any carbon black such as those commercially available from the art may be used in the present invention.

Component (c) of the carbon black masterbatch of the invention is a polymer of vinyl aromatic monomers. Component (c) of the invention preferably is a thermoplastic polymer that it is miscible with component (a). For example, component (c) of the invention is a copolymer of vinyl aromatic monomers, such as copolymers of vinyl aromatic monomers and one or more commoners having functional groups, such as unsaturated carboxylic acid and /or unsaturated carboxylic acid derivatives.

Without being intended to be bound by any theory, it is surprisingly found that, when component (c) of the invention, a polymer of vinyl aromatic monomers, is added into a carbon black masterbatch for a fiber dope, especially polyamide island fiber dope, the concentration of the carbon black in the dope will be improved greatly, and the obtained fiber from the dope has darker and more uniform color as compared with those in the art, at the same time maintain the desired fiber properties, such as fiber strength.

In a preferred embodiment of the invention, the component (c) of the carbon black masterbatch of the invention is a copolymer of a vinyl aromatic monomer and a (meth)acrylate; preferably the vinyl aromatic monomer is an non-substituted styrene or styrene substituted with one or more groups selected from the group consisting of methyl, ethyl and propyl, more preferably methyl or ethyl; and preferably the alcohol moiety in the (meth)acrylate is derived from Ci-Cio alkyl alcohol, preferably C ₁ -C4 alkyl alcohol, more preferably methyl alcohol, ethyl alcohol, and propyl alcohol, butyl alcohol, and 2-ethyl hexyl alcohol. Also within the scope of the invention, in some embodiments of the invention, the (meth)acrylate means (meth)acrylic acid. In another preferred embodiment of the invention, the component (c) of the carbon black masterbatch of the invention is styrene-(meth)acrylate copolymer.

In an other embodiment of the invention, the component (c) of the carbon black masterbatch of the invention is a copolymer of a vinyl aromatic monomer and a (meth)acrylic acid, preferably the vinyl aromatic monomer is an non-substituted styrene or styrene substituted with one or more groups selected from the group consisting of methyl, ethyl and propyl, more preferably methyl or ethyl.

In some preferred embodiments of the invention wherein the component (c) of the carbon black masterbatch of the invention is a copolymer of a vinyl aromatic monomer and a (meth)acrylate, the molar ratio of vinyl aromatic monomer to (meth)acrylate polymerized into the component (c) of the invention may be in the range of about 1 : 100 to about 100: 1, preferably about 1 : 10 to about 10: 1, more preferably about 1 :5 to about 5: 1, or it is about 1 : 1. Preferably, products of ADF series from BASF Auxiliary Chemical Co., Ltd., Shanghai, China are suitable as component (c) of the carbon black masterbatch of the invention. Preferably, Joncryl ADF from BASF Auxiliary Chemical Co., Ltd. is used as component (c) of the carbon black masterbatch of the invention.

In still some preferred embodiments of the invention, preferably, in the copolymer of a vinyl aromatic monomer and a (meth)acrylate used as component (c) of the carbon black masterbatch of the invention, the amount of monomeric units from (meth)acrylate is in the range of 0 to 60 percent by weight, preferably it is in the range of 0 to 50 percent by weight, more preferably 0 to 35 percent by weight, based on the weight of the copolymer.

In yet other embodiments of the invention, the component (c) of the carbon black masterbatch of the invention is polystyrene, preferably having the number average molecular weight Mn of 1,500-10,000, preferably 1,500 to 8,000, more preferably 5,000 to 8,000, most preferably 5,000.

In present invention, the component (c) of the carbon black masterbatch of the invention may preferably have the number average molecular weight of from about 1,000 to about 20,000, preferably 1,500 or more, more preferably 3,000 or more, most preferably 5,000 or more, or about 6,000, and about 18,000 or less, more preferably about 10,000 or less, or 10,000or less, such as 5,000 to 8,000, as determined by gel permeation chromatography. Also appropriate, in some embodiments, the number average molecular weight of the component (c) of the carbon black masterbatch suitable for the purpose of the invention may in the range of 1,000 to 9,000, preferably 3,000 to 8, 500, or 4,000 to 8,000, more preferably 5000.

The component (c) of the carbon black masterbatch of the invention may be obtained by any polymerization process known to a skilled person in the art, including bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization. For example, in an embodiment of the invention wherein the component (c) of the invention is a styrene-(meth)acrylate copolymer, the copolymer is obtainable in any one of these polymerizations. For example, in the bulk polymerization, the styrene-(meth)acrylate copolymer is obtained by mixing styrene and (meth)acrylate monomers and polymerizing the obtained mixture in the presence of initiator. In solution polymerization, the styrene-(meth)acrylate copolymer is obtained by dissolving styrene and (meth)acrylate monomers into toluene (benzene /methyl alcohol) solution and polymerizing in the presence of initiator (e.g, CN1995075A, herein incorporated by reference in entirety).

In the present invention, the amount of component (a) in the carbon black masterbatch may be up to 85% by weight of the carbon black masterbatch, preferably up to 80%>, more preferably up to 75%, most preferably up to 70%, by weight of the carbon black masterbatch. The amount of component (a) in the carbon black masterbatch of the invention may be at least 40% by weight of the carbon black masterbatch, preferably at least 50%, more preferably at least 55%, most preferably at least 60% by weight of the carbon black masterbatch of the invention.

In the present invention, the amount of component (b) in the carbon black masterbatch may be up to 50% by weight of the carbon black masterbatch, preferably up to 45%, more preferably up to 40%, most preferably up to 35%, by weight of the carbon black masterbatch. The amount of component (b) in the carbon black masterbatch of the invention may be at least 15% by weight of the carbon black masterbatch of the invention, preferably at least 18%, more preferably at least 20%, most preferably at least 25% by weight of the carbon black masterbatch of the invention.

In the present invention, the amount of component (c) in the carbon black masterbatch may be up to 10% by weight of the carbon black masterbatch, preferably up to 8%, more preferably up to 6%), most preferably up to 5%, such as up to 4%, by weight of the carbon black masterbatch. The amount of component (c) in the carbon black masterbatch of the invention may be at least 0.1% by weight of the carbon black masterbatch, preferably at least 0.2%, more preferably at least 0.5%, most preferably at least 1% by weight of the carbon black masterbatch. In a preferred embodiment of the invention, the amount of component (c) in the carbon black masterbatch is 1.4% by weight of the carbon black masterbatch.

In a preferred embodiment of the invention, the amount of the component (a) in the carbon black masterbatch of the invention is 69%, the amount of component (b) in the carbon black masterbatch is 30%, and the amount of component (c) in the carbon black masterbatch is 1.0%.

Optionally, other additives may be used in the carbon black masterbatch of the invention, such as antioxidant, antistatic agent, UV-absorbing agent and the like.

Suitable antioxidants include phosphorus based antioxidants, phenolic antioxidants and sulfur based antioxidants. Examples of phosphorus-based antioxidants including a monophosphites and diphosphates, such as, tris(2,4-di-tert-butylphenyl)phosphate (Antioxidant 168) and tris(mono/di-nonylphenyl)phosphate (such as Antioxidant TNP), distearyl pentaerythritol diphosphite; dioctyl pentaerythritol diphosphite; diphenyl pentaerythritol diphosphite; bis(2,4-di-tertbutylphenyl) pentaerythritol diphosphite; bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, dicyclohexyl pentaerythritol diphosphite; tris(2,4-di-tert-butylphenyl)phosphite; tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene phosphite.

Suitable phenolic antioxidants include, 2,2'-methylenebis(6-tert-butyl-4-methylphenol); 1 , 1 -bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane;

2,2'-methylenebis(4-methyl-6-cyclohexylphenol); 4,4'-thiobis(6-tert-butyl-3-methylphenol),

2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenol)-4-n-dodecy lmercapto-butane,

2,6-di-tert-4-methylphenol; 2,2'-methylenebis(6-tert-butyl-4-ethylphenol);

2,2'-methylene-bis>4-methyl-6-(.alpha.-methylcyclohexy l)phenol;

2,2'-methylenebis(4-methyl-6-nonylphenol);

1 , 1 ,3-tris-(5-tertbutyl-4-hydroxy-2-methylphenyl)butane;

ethyleneglyco l-bis>3 ,3 -bis(3 -tert-butyl-4-hydroxyphenyl)butyrate;

1 - 1 -bis(3 ,5 -dimethyl-2-hydroxyphenyl)-3 -(n-dodecylthio)-butane; 1 ,3 ,5 -tris(3 ,5 -di-tert-butyl-4-hydr oxybenzyl)-2,4,6-trimetylbenzene; 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)dioctadecyl malonate ester; n-octadecyl-3-(4-hydroxy-3,5-di-tert-butylphenyl)propionate, tetrakis-methylene(3 ,5-di-tert-butyl-4-hydroxyhydrocinnamate)methane (Antioxidant 1010), 3,9-bis- 1 , 1 -dimethyl-2-(P-(3-tert-butyl-4-hydroxy-5-methylphenyl)propio nyloxy)ethyl-2,4,8, 10-tetr oxaspiro>5,5-undecane, tris-(3,5-di-tert-butyl-4-hydroxylenzyl)isocyanurate, 2,6-diphenyl-4-methoxyphenol, and tris-(4-tert- butyl-2,6-dimethyl-3-hydroxybenzyl)-isocyanurate.

Suitable sulfur-based antioxidants include: dilauryl-3,3'-thiodipropionate; dimyristyl-3 ,3 '-thiodipropionate, distearyl-3 ,3 '-thiodipropionate, pentaerythritol-tetrakis-(P-laurylthiopropionate),

bis>2-methyl-4-(3-n-alkylthiopropionyloxy)-5-tert-buty lphenylsulfide, and 2-1 mercaptobenzimidazo le.

Other suitable antioxidants are, such as, Antioxidant 163.

The antistatic agents suitable for the carbon black masterbatch of the invention may be one or more antistatic agents selected from the group consisting of fatty alcohol phosphate, fatty alcohol alkylene oxide ether phosphate salt, fatty alcohol Potassium phosphate, stearic acid mono-glyceride, and polyethylene glycol.

The UV-absorbing agents suitable for the carbon black masterbatch of the invention may be one or more UV-absorbing agents selected from the group consisting of organic aromatic substance such as benzotriazoles and benzophenone, zinc oxide and titanium oxide.

The other additives may be incorporated into the carbon black masterbatch at any appropriate time during the formation of the carbon black masterbatch of the invention.

If present, the amount of the other additives in the carbon black masterbatch of the present invention may be in the range of 0-10 percent by weight, preferably 0-5 percent by weight, more preferably 0-2.5 percent by weight, such as 0.001 to 1 percent by weight, based on the total weight of the carbon black masterbatch.

The carbon black masterbatch of the invention may be formed by any suitable method in the art. For example, in an embodiment, the component (a), the component (b) and the component (c) are added together to a high mixer to form a blend, then the formed blend is send to a twin screw extruder for melting, extruding and pelletizing to obtain the carbon black masterbatch of the invention in pelleted form. Alternatively, the component (a) and the component (b) are mixed and melted together at first, then component (c) is added to the melt of the component (a) and the component (b) to obtain the carbon black masterbatch of the invention.

In the second aspect of the invention, the present invention relates to a dope for making an island fiber, comprising:

(1) the carbon black masterbatch of the invention;

(2) a polyamide; and

(3) a polymer for forming sea in making the island fiber.

Component (2) of the dope of the invention is a polyamide selected from the same group as defined above for component (a) in the carbon black masterbatch of the invention. Preferably, in the present invention, component (2) in the dope and the component (a) in the carbon black masterbatch are of the same polyamide.

In the present invention, the amount of the component (1) in the dope of the invention may be at most 50%, preferably at most 40%, more preferably at most 35%; most preferably at most 30%, by weight of the dope of the present invention, and may be at least 15%, preferably at least 18%, more preferably at least 20%; most preferably at least 25%, by weight of the dope of the present invention. In a preferred embodiment of the invention, the amount of the component (1) in the dope of the invention is 28%, by weight of the dope of the present invention.

In the present invention, the total amount of the component (2) and component (3) in the dope of the invention may be at most 85%, more preferably at most 80%; most preferably at most 70%, by weight of the dope of the present invention, and may be at least 50%, preferably at least 55%, more preferably at least 60%; most preferably at least 65%, by weight of the dope of the present invention. The weight ratio of the component (2) to component (3) in the dope of the invention is not critical, provide that they will form an island fiber, and it can be selected by a skilled person according to practical application.

In the dope of the invention, any material that can be used for forming sea of an island fiber with component (2) is suitable for component (3). A skilled person can select appropriate materials to be used as component (3) according to practical application. For example, but not limit to, the component (3) may be polyolefms, for example polya-olefins, such as polyethylene (PE), polypropylene (PP), preferably PE; and polyester, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT ). The present invention also relates to an island fiber obtainable from the dope of the invention. With the carbon black masterbatch of the invention, the carbon black may be present in the obtained island fiber in an amount of up to 10%, such as up to 8%, especially up to 6%> by weight of the total weight of the island fiber. Compared with the island fiber in the art, the island fiber of the invention will have darker and uniform color, substantially black or pure black, with the stable spinning properties and excellent fiber properties.

In an exemplary embodiment of the invention, the carbon black masterbatch of the invention is at first dried in a honeycomb oven (Model PD60, commercial available from Suzhou Tongyi mechanical equipments Co. Ltd.) at 90°C for 12 hours, to reduce the moisture to less than 50ppm. Then the dried carbon black masterbatch is mixed with component (2) and component (3) to form a dope.

In the third aspect of the invention, the present invention relates to a process for making an island fiber, comprising the step of spinning the dope of the invention.

The spinning process for making the island fiber of the invention may be any process known in the art, such as melt spinning, dry spinning and the like, provided that the process comprises the step of spinning the dope of the invention. Melt spinning is preferred.

In a preferred embodiment of the invention, the process of the invention comprises the steps of:

(a) preparing the carbon black masterbatch of the invention;

(b) mixing the carbon black masterbatch, polyamide and a polymer for forming sea in making the island fiber to form a blend;

(c) melting the blend obtained in step (b) to form a dope; and

(d) spinning the dope obtained in step (c).

After step (d), generally the obtained firers are treated in a solvent to remove the polymer for forming sea in making the island fiber. Then the treated fibers are filtered and dried to obtain the island fiber.

To sum up, the present invention includes the following embodiments.

1. a carbon black masterbatch, comprising:

(a) a polyamide,

(b) carbon black, and

(c) a polymer of vinyl aromatic monomers,

wherein component (c) is a thermoplastic polymer that is miscible in component (a).

2. The carbon black masterbatch of embodiment 1, wherein the amount of component (a) in the carbon black masterbatch is up to 85%, preferably up to 80%), more preferably up to 75%, most preferably up to 70%>, by weight of the carbon black masterbatch, and at least 40%, preferably at least 50%, more preferably at least 55%, most preferably at least 60% by weight of the carbon black masterbatch;

the amount of component (b) in the carbon black masterbatch is up to 50%, preferably up to 45%), more preferably up to 40%>, most preferably up to 35%, by weight of the carbon black masterbatch, and at least 15%, preferably at least 18%, more preferably at least 20%, most preferably at least 25% by weight of the carbon black masterbatch; and

the amount of component (c) in the carbon black masterbatch is up to 10%, preferably up to 8%), more preferably up to 6%, most preferably up to 5%, such as up to 4%, by weight of the carbon black masterbatch, and at least 0.1% by weight of the carbon black masterbatch, preferably at least 0.2%, more preferably at least 0.5%, most preferably at least 1% by weight of the carbon black masterbatch.

3. The carbon black masterbatch of any one of embodiments 1-2, wherein the number average molecular weight of the component (c) is from about 1,000 to about 20,000, preferably 1,500 or more, more preferably 3,000 or more, most preferably 5,000 or more, or about 6,000, and about 18,000 or less, more preferably about 10,000 or less, or 10,000or less, such as 5,000 to 8,000, preferably the number average molecular weight of the component (c) is in the range of 1,000 to 9,000, preferably 3,000 to 8, 500, or 4,000 to 8,000, more preferably 5000.

4. The carbon black masterbatch of any one of embodiments 1-3, wherein component (c) is a copolymer of a vinyl aromatic monomer and a (meth)acrylate; preferably the vinyl aromatic monomer is an non-substituted styrene or styrene substituted with one or more groups selected from the group consisting of methyl, ethyl and propyl, more preferably methyl or ethyl; and preferably the alcohol moiety in the (meth)acrylate is derived from Ci-Cio alkyl alcohol, preferably C1-C4 alkyl alcohol, more preferably methyl alcohol, ethyl alcohol, and propyl alcohol, butyl alcohol, and 2-ethyl hexyl alcohol, or the (meth)acrylate is (meth)acrylic acid.

5. The carbon black masterbatch of embodiment 4, wherein the molar ratio of vinyl aromatic monomer to (meth)acrylate polymerized into the copolymer is in the range of about 1 : 100 to about 100: 1, preferably about 1 : 10 to about 10: 1, more preferably about 1 :5 to about 5: 1, or it is about 1 : 1.

6. The carbon black masterbatch of embodiment 4, wherein the copolymer comprises monomeric units from (meth)acrylate in amount of 0 to 60 percent by weight, preferably 0 to 50 percent by weight, more preferably 0 to 35 percent by weight, based on the weight of the copolymer.

7. The carbon black masterbatch of any one of embodiments 1-3, wherein component (c) is polystyrene, preferably having the number average molecular weight of 1,500-10,000, preferably 1,500 to 8,000, more preferably 5,000 to 8,000, most preferably 5,000. 8. The carbon black masterbatch of any one of embodiments 1-7, further containing one or more of other additives, such as antioxidant, antistatic agent, and UV-absorbing agent.

9. The carbon black masterbatch of embodiment 8, wherein the antioxidant is selected from phosphorus based antioxidants, phenolic antioxidants, sulfur based antioxidants and Antioxidant 163.

10. The carbon black masterbatch of embodiment 8 or 9, wherein the amount of the other additive in the composition is in the range of 0-10 percent by weight, preferably 0-5 percent by weight, more preferably 0-2.5 percent by weight, such as 0.001 to 1 percent by weight, based on the total weight of the carbon black masterbatch.

11. The carbon black masterbatch of any one of embodiments 1-10, wherein the component (a) has moisture of less than 300ppm, based on the weight of the component (a).

12. a dope for making an island fiber, comprising:

(1) the carbon black masterbatch of any one of embodiments 1-11;

(2) a polyamide; and

(3) a polymer for forming sea in making the island fiber.

13. the dope of embodiment 12, wherein component (2) in the dope and the component (a) in the carbon black masterbatch are of the same polyamide, preferably the polyamide is PA6.

14. the dope of embodiment 12 or embodiment 13, wherein

the amount of the component (1) is at most 50%, preferably at most 40%, more preferably at most 35%; most preferably at most 30%>, by weight of the dope, and is at least 15%, preferably at least 18%), more preferably at least 20%; most preferably at least 25%, by weight of the dope, preferably the amount of the component (1) is 28%, by weight of the dope; and

the total amount of the component (2) and component (3) is at most 85%, more preferably at most 80%; most preferably at most 70%, by weight of the dope, and is at least 50%, preferably at least 55%), more preferably at least 60%; most preferably at least 65%, by weight of the dope.

15. The dope of any one of embodiments 12-14, wherein the component (3) in the dope is selected from the group consisting of polyolefms and polyester, preferably is selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, and polybutylene terephthalate, more preferably the component (3) is polyethylene.

16. a process for making an island fiber, comprising the step of spinning the dope of any one of embodiments 12-15.

17. the process of embodiment 16, comprising the step of:

(a) preparing the carbon black masterbatch of any one of embodiments 1-11;

(b) mixing the carbon black masterbatch, polyamide and a polymer for forming sea in making the island fiber to form a blend;

(c) melting the blend obtained in step (c) to form a dope; and

(d) spinning the dope obtained in step (d).

18. An island fiber made from the dope defined according to any one of embodiments 12-15, or made from the process of any one of embodiments 16-17, wherein the island fiber has carbon black in an amount of up to 10%, such as up to 8%, especially up to 6%> by weight of the total weight of the island fiber.

19. Use of the carbon black masterbatch of any one of embodiments 1-11 for making an island fiber.

20. Use of the dope of any one of embodiments 12-15 for making an island fiber.

21. An article, prepared from the island fiber of embodiment 14.

ADVANTAGES OF THE INVENTION

The present invention has following advantages:

1. providing a new carbon black masterbatch in a dope for fiber application, such as for island fiber application, especially for PA/PE island fiber application. Compared with the prior art, the carbon black masterbatch of the invention can be produced at low cost and has stable quality.

2. commercially available common carbon black may be used for the carbon black masterbatch of the invention, without the need of costly pretreating step for the carbon black to improve the dispersibility of the carbon black before producing the masterbatch.

3. the amount of the carbon black in a dope for a fiber application is increased, and the fiber obtained from the invention has darker and more uniform color as compared with the prior art. At the same time the stable good qualities, such as the desired strength, of the obtained fiber are maintained.

4. In addition to the improved color, the flowability of the carbon black masterbatch of the invention is improved and whereby the flowability of the dope is improved when the dope is extruded through the spinneret, thus no spinneret plate jam or broken filament will occur.

EXAMPLES

The present invention will be further illustrated hereinafter with the reference of the specific examples which are exemplary and explanatory only and are not restrictive.

Each part and percentage when used, if not defined otherwise, is provided on weight basis.

Materials and apparatus that were used:

Polyamide (component (a) of the carbon black masterbatch): high-speed spinning purity PA6 platelets commercially available from Taiwan JiSheng Corp., Taiwan.

Carbon black (component (b) of the carbon black masterbatch): carbon black of spinning grade, commercial available from Shanghai Cabot Chemical Co., Ltd, Shanghai China, under the brand BP3560.

Component (c) of the carbon black masterbatch: Jocnryl ADF having Mn of 4500, commercially available from BASF Auxiliary Chemical Co., Ltd., Shanghai, China.

LDPE: commercially available from Saudi Basic Industry Corporation, Riyadh, Saudi Arabia, with the trade name of HP2027N.

The twin screw extruder: JW4/600, commercially available from Jingwei Textile Machinery Co., Ltd. Beijing China.

Pvheometer machine: Malvern Model RH7, commercial available from Malvern Instruments Ltd. Shanghai China.

Example 1. Preparation of carbon black masterbatch 1 (inventive)

Formulation 1: PA6 (Polyamide 6)+30 wt %carbon black+0.7 wt % Jocnryl ADF

Process:

(a) , drying PA6 in an oven for 12 hours at 90°C such that the moisture of this PA6 is less than 300ppm;

(b) . mixing 1.386kg dried PA6 from step (a), 0.6kg carbon black and 0.014kg Joncryl ADF in a high mixer for 2 min at 600rpm to obtain a blend;

(c) . sending the obtained blend to a twin screw extruder and pelletizing the extruded blend to form granules of a carbon black masterbatch, wherein the operating temperature of the twin screw extruder is about 250°C, the pressure at the die of the twin screw extruder is about 55 bar, screw speed is about 240rpm, and feeding speed is about 15 rpm;

(d) . collecting the granules of carbon black masterbatch and drying them in an oven for 12 hours at 90°C to obtain carbon black masterbatch 1.

The obtained carbon black masterbatch 1 was stored in an aluminum bag.

Example 2. Preparation of carbon black masterbatch 2 (inventive)

Formulation 2: PA6 (Polyamide 6)+30 wt %carbon black+1.4 wt %Jocnryl ADF

Process:

(a), drying PA6 in an oven for 12 hours at 90°C such that the moisture of this PA6 is less than 300ppm;

(b) . mixing 1.372 dried PA6 from step (a), 0.6kg carbon black and 0.028kg Joncryl ADF in a high mixer for 2 min at 600rpm to obtain a blend;

(c) . sending the obtained blend to a twin screw extruder and pelletizing the extruded blend to form granules of a carbon black masterbatch wherein the operating temperature of the twin screw extruder is about 250°C, the pressure at the die of the twin screw extruder is about 55bar, screw speed is about 240rpm, and feeding speed is about 15rpm.

(d) . collecting the granules of carbon black masterbatch and drying them in an oven for 12 hours at 90°C to obtain carbon black masterbatch 2.

The obtained carbon black masterbatch 2 was stored in an aluminum bag.

Example 3. Preparation of carbon black masterbatch 3 (inventive)

Formulation 3: PA6(Polyamide 6)+35 wt %carbon black+0.7 wt %JocnrylADF

Process:

(a) , drying PA6 in an oven for 12 hours at 90°C such that the moisture of this PA6 is less than 300ppm;

(b) . mixing 1.286 dried PA6 from step (a), 0.7kg carbon black and 0.014kg JoncrylADF in a high mixer for 2 min at 600rpm to obtain a blend;

(c) . sending the obtained blend to a twin screw extruder and pelletizing the extruded blend to form granules of a carbon black masterbatch wherein the operating temperature of the twin screw extruder is about 250°C, the pressure at the die of the twin screw extruder is about 50-60 bar, screw speed is about 240rpm, and feeding speed is about 15rpm;

(d) . collecting the granules of carbon black masterbatch and drying them in an oven for 12 hours at 90°C to obtain carbon black masterbatch 3.

The obtained carbon black masterbatch 3 was stored in an aluminum bag.

Example 4. Preparation of carbon black masterbatch 4 (inventive)

Formulation 4: PA6(Polyamide 6)+35 wt %carbon black+2.5 wt % Jocnryl ADF

Carbon black masterbatch 4 was prepared by the process of example 1, except that the formulation was Formulation 4:

PA6(Polyamide 6)+35 wt %carbon black+2.5 wt %JocnrylADF. Example 5. Preparation of carbon black masterbatch A (comparative)

Formulation A: PA6 (polyamide 6)+30 wt %carbon black

Preparation process:

(a) . Drying PA6 in an oven for 12 hours at 90°C such that the moisture of this PA6 is less than 300ppm;

(b) . mixing 1.4 kg dried PA6 from step (a) and 0.6kg carbon black in a high mixer for 2 min at 600rpm to obtain a blend;

(c) . sending the obtained blend to a twin screw extruder and pelletizing the extruded blend to form granules of a carbon black masterbatch, wherein the operating temperature of the twin screw extruder is about 250°C, the pressure at the Die of the twin screw extruder is about 60-70 bar , screw speed is about 240rpm, feeding speed is about 15rpm.

(d) . Collecting the granules of carbon black masterbatch and drying them in an oven for 12 hours at 90°C to obtain carbon black masterbatch A.

The obtained carbon black masterbatch A was stored in an aluminum bag.

Example 6. test of the shear viscosity

The shear viscosity of each of the carbon black masterbatchs from above examples 1-4 was tested using a rheometer machine (malvern RH7).

Shear viscosity test condition:

— Test temperature in the barrel of the rheometer machine: 260°C

— Left die size: 1.0(mm, inner diameter of the capillary inside the die) ^x 16(mm, the height of the die) ^x 180(°, angle of the die) ^x 15 (mm, diameter of the die); Right die size: 1.0(mm, inner diameter of the capillary inside the die) ^x 0.25(mm, the height of the die) ^x 180(°, angle of the die)x l5(mm, diameter of the die)

— Pretreatment for material in the barrel:

Before testing, the carbon black masterbatch to be tested was pretreated inside the barrel of the rheometer machine. First, the carbon black masterbatch was compressed by a compression bar of the rheometer machine to 0.5mpa and then the compression was stopped and kept waiting for 2 min. Then, the carbon black masterbatch was again compressed by the compression bar to 0.5 mpa and then the compression was stopped and kept waiting for 1 min. By the pretreatment, the carbon black masterbatch inside the barrel was heated homogeneously and was compressed.

The shear viscosity of each of the carbon black masterbatch is reported in table 1. Table 1

Conclusion:

Comparing the above carbon black masterbatchs having the same concentration of carbon black as that of carbon black masterbatch A with carbon black masterbatch A in table 1, it can be seen that the more JocnrylADF added to the carbon black masterbatchs, the lower shear viscosity of carbon black masterbatch obtained.

Comparing the above carbon black masterbatchs having different concentration of carbon black with carbon black masterbatch A in table 1 , it can be seen that the carbon black masterbatch of the invention has greatly decreased shear viscosity as compared with carbon black masterbatch A, even if the carbon black masterbatch of the invention has higher carbon black concentration that the carbon black masterbatch A.

The result means that the carbon black masterbatch of the invention can have higher dispersibility at higher carbon black concentration as compared with the prior art carbon black concentration without Joncryl ADF.

Following examples 7-11 demonstrate the performance of the carbon black masterbatch of the invention in an island fiber.

Example 7

The mixture of 20 parts by weight of carbon black masterbatch 1 obtained from example 1 and 40 parts by weight of polyamide 6 was dried at 90°C for 12 hours. After that, the mixture was blended with 40 parts by weight of LDPE. The obtained blend was passed to the inlet of a spinning machine (JW4/600, commercially available from Jingwei Textile Machinery Co., Ltd. Beijing China) to form dope 1 for spinning. The spinning machine sequentially had five sections, inlet section at temperature of 270°C, melting section I at temperature of 275 °C, melting section II at temperature of 275°C, connecting pipe at temperature of 275°C and spinneret at temperature of 275°C.

In the example, the winding up speed of the obtained fiber was 800m/min, speed of the annular blowing air was 0.6m/s, temperature of the annular blowing air was in a range of 18-22°C. Melt spinning pressure was 1.35bar.

Spec of the spinneret: diameter of the fluid directing opening was 2.45mm, and diameter of fiber exiting opening was 0.35mm, the number of pore of the spinneret was 36.

The properties of the obtained fiber were tested, and the results were reported in following table 2.

Examples 8-11

Examples 8-11 were carried out with the above obtained carbon black masterbatch 2, carbon black masterbatch 3, carbon black masterbatch 4 and carbon black masterbatch A.

Examples 8-11 were carried according to the procedure employed in example 7, except that the melt spinning pressure for example 8 was 2.30bar; the melt spinning pressure for example 9 was 3.33bar; the melt spinning pressure for example 10 was 2.45bar; and the melt spinning pressure for example 11 was 2.40bar.

The dopes obtained from examples 8-11 were dope 2, dope 3, dope 4, dope A, respectively.

The properties of the obtained fiber were tested, and the results were reported in following table 2. Table 2

18D/36F: the measured island fiber was of 18 deniers, and consisted of 36 filaments.

Not stable* : which means that during spinning, broken filaments appeared or the spinneret plate was jammed for two times or more in 10 hours.

-: the obtained island fiber was broken and the properties thereof could not be measured.

The strength of the filament of each obtained island fiber was measured by Instron, Model 5566 from INSTRON CORPORATION, US, according to ASTM D2256. The value reported in table 2 was the average of three measured values. According to Customer's requirements, the tensile strength in the range of 2.0-2.9 dtex/CN will be appropriate.

Concentration of Carbon black: Tested by TGA equipment (type: Pyris 1 from PerkinElmer Company, Massachusetts, US).

Each of the documents referred to above is incorporated herein by reference.

Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about".

It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements.

The present invention is not to be limited in scope by the specific embodiments and examples described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims.