CN107881594B

CN107881594B - Acid-resistant and wear-resistant abrasive wire

Info

Publication number: CN107881594B
Application number: CN201610879105.8A
Authority: CN
Inventors: 金媛; 田文伟; 阎惠至
Original assignee: DuPont Xingda Filaments Co Ltd
Current assignee: Celanese Xingda Wuxi Monofilament Co ltd; DuPont
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2021-08-06
Anticipated expiration: 2036-09-30
Also published as: CN107881594A

Abstract

The present invention relates to an abrasive filament comprising: (a) about 55-95 wt% polyamide 610, (b) about 1-10 wt% polyethylene, (c) about 1-10 wt% thermoplastic elastomer, and (d) about 0.1-35 wt% of other additives selected from abrasive particles, compatibilizers, anti-hydrolysis agents, and mixtures thereof; wherein the weight% is based on the total weight of the abrasive filament.

Description

Acid-resistant and wear-resistant abrasive wire

Technical Field

The present invention relates to an abrasive wire, and more particularly, to an abrasive wire having improved acid and wear resistance. The invention also relates to a manufacturing method of the abrasive wire.

Background

The abrasive filaments are widely used in industry, and are mainly used for dust-proof, polishing, cleaning or grinding treatment of the surface of a workpiece to be ground, such as marble, metal, electronic components and the like. Abrasive filaments are generally produced by a melt spinning method using a thermoplastic resin, abrasive particles, or the like as a main raw material. The industry has primarily used abrasive filaments for finishing, polishing, lapping, deburring, chamfering, and the like of metal workpieces. When the abrasive wire is used to abrade a surface to be treated, it is sometimes necessary to spray an acidic solution such as sulfuric acid or hydrochloric acid to the surface to be treated to accelerate removal of rust, dirt, or the like on the surface to be treated, which is difficult to remove, and in such a case, the abrasive wire is required to have a certain acid resistance.

CN104562286A discloses an abrasive filament obtained by adding abrasive particles to a mixture of polyethylene and polyamide and then melt-spinning the obtained resin composition.

The inventors of the present invention have found that the above prior art abrasive filaments are susceptible to degradation when abraded under acidic conditions, such as by spraying the treated surface with an acidic solution, resulting in breakage or significant wear of the treated surface, such that the useful life of the abrasive filament or an abrasive brush made from the abrasive filament is low.

Accordingly, there remains a need in the art for an abrasive filament that exhibits improved acid and wear resistance when abraded under acidic conditions on a treated surface.

Disclosure of Invention

The present invention provides an abrasive filament comprising:

(a) about 55 to about 95 weight percent of polyamide 610;

(b) about 1-10 wt% polyethylene;

(c) about 1-10 wt% of a thermoplastic elastomer; and

(d) about 0.1-35% by weight of other additives selected from abrasive particles, compatibilizers, hydrolysis resistance agents, and mixtures thereof;

wherein the weight% is based on the total weight of the abrasive filament.

The invention also provides a method for manufacturing the abrasive wire.

Detailed Description

All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if fully set forth herein, if not otherwise indicated.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

All percentages, parts, ratios, etc., are by weight unless otherwise indicated.

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

The conjunction "consisting of" does not include any unspecified elements, steps or components. If in the claims, such conjunctions would render the claims dependent upon the recited material, except for impurities normally associated therewith. When the phrase "consisting of" appears in a clause of the characterizing portion of the claims, rather than following the preamble, it is limited only to the elements listed in that clause; other elements are not excluded from the claim as a whole. The conjunction "consisting essentially of" is used to define a composition, method or apparatus that includes materials, steps, features, components or elements other than those literally discussed, provided that such additional materials, steps, features, components or elements do not materially affect the basic and novel characteristics of the claimed invention. The term "consisting essentially of" lies in a range intermediate between "comprising" and "consisting of.

The term "comprising" includes embodiments encompassed by the term "consisting essentially of and" consisting of. Similarly, the term "consisting essentially of includes embodiments encompassed by the term" consisting of.

When an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of an upper range limit or preferred value and a lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1-5" is recited, the disclosed range should be understood to include "1-4", "1-3", "1-2 and 4-5", "1-3 and 5", and so forth. Where a range of numerical values is recited in the specification, unless otherwise stated, the range is intended to include the endpoints of the range and all integers and fractions within the range.

When the term "about" is used to describe a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to.

Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive "or" and not to an exclusive "or". For example, any of the following satisfies the condition of a "or" B: a is true (or present) and B is false (or not present), a is false (or not present) and B is true (or present), and both a and B are true (present).

Embodiments of the invention described in the summary of the invention section include any other embodiments described herein and can be combined in any manner, and the subject matter in the embodiments describes abrasive filaments of the invention.

The invention is described in detail below:

the abrasive filaments of the present invention comprise: (a) about 55 to about 95 weight percent of polyamide 610; (b) about 1-10 wt% polyethylene; (c) about 1-10 wt% of a thermoplastic elastomer; and (d) about 0.1 to 35 weight percent of other additives selected from the group consisting of abrasive particles, compatibilizers, hydrolysis resistance agents, and mixtures thereof; wherein the weight% is based on the total weight of the abrasive filament.

(a) Polyamide 610

In the present invention, the base resin of the abrasive filament is polyamide 610, which is prepared by polymerization of hexamethylene diamine and sebacic acid. The polyamide 610 may be made according to any method known in the art. The production method includes a polycondensation reaction method or a stepwise polymerization reaction method using the corresponding hexamethylenediamine and sebacic acid as raw materials. If necessary, a catalyst or the like may be used in the production method.

According to the present invention, there is no limitation on the intrinsic viscosity of the polyamide 610 as long as it enables the finally obtained abrasive composition to be spun by a spinning method (preferably, a melt spinning method). The relative viscosity of the polyamide 610 may be about 1.5 to 3.7, or about 1.7 to 3.4, or about 2.1 to 3.0. In the present invention, the relative viscosity is a measure of the change in solution viscosity caused by the polymer entering the solution, and is generally expressed by the ratio of the polymer solution viscosity to the pure solution viscosity, and the greater the relative viscosity, the greater the relative molecular weight of the polymer.

Polyamides 610 suitable for the present invention may also be obtained from commercial sources, such as those available from Dupont Dada (tin-free) monofilaments, Inc

Polyamide 610 available from basf corporation under the trade name

Or a spinning grade polyamide 610 obtained from engineering plastics ltd, east of shandong.

In one embodiment of the present invention, the abrasive filament comprises about 55 to 95 weight percent polyamide 610, or about 58 to 92 weight percent polyamide 610, wherein the weight percent is based on the total weight of the abrasive filament.

(b) Polyethylene

In the present invention, the polyethylene may be selected from the group consisting of Linear Low Density Polyethylene (LLDPE), Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), Ultra High Molecular Weight Polyethylene (UHMWPE), Ultra Low Density Polyethylene (ULDPE), and mixtures thereof; among them, linear low density polyethylene is preferable.

According to the present invention, the polyethylene may be used in only one kind, or may be used in combination of two or more kinds.

According to the present invention, there is no limitation in the molecular weight and the like of the polyethylene as long as it enables the finally obtained abrasive composition to be spun by a spinning method. The person skilled in the art can select any suitable polyethylene from the prior art depending on the actual spinning situation. For example, the weight average molecular weight (M) of the polyethylene_w) May be about 30000-1000000, preferably about 50000-200000, and the Melt Index (Melt Flow Index, determined according to ISO1133-1:2001 standard method) may be about 0.1-100g/10min, preferably about 1-10g/10min, but is sometimes not limited thereto.

According to the invention, the polyethylene may be obtained from commercial sources, for example fromThe product of ExxonMobil manufactured by ExxonMobil corporation^TMLLDPE LL 1002YB, LLDPE LL 6201XR, or LDPE LD 654, polyethylene available under the trade designation LDPE 2420H from Zhonghai Shell petrochemical company Limited.

In one embodiment of the present invention, the abrasive filament comprises about 1 to 10 wt% polyethylene, or about 3 to 7 wt% polyethylene, wherein the wt% is based on the total weight of the abrasive filament.

(c) Thermoplastic elastomer

In the present invention, the thermoplastic elastomer is selected from copolyether ester (TPEE), Thermoplastic Polyurethane (TPU), Thermoplastic Polyolefin (TPO), Thermoplastic Polystyrene (TPS), and mixtures thereof; among them, copolyetheresters are preferred.

According to the present invention, the thermoplastic elastomer may be used alone or in combination of two or more.

Copolyetheresters suitable for the present invention can be copolymers having a plurality of repeating long-chain ester units and repeating short-chain ester units joined head-to-tail through ester linkages. In one embodiment of the invention, the copolyetheresters contain from about 1% to about 85% by weight of said recurring long-chain ester units and from about 15% to about 99% by weight of said recurring short-chain ester units, or from about 5% to about 80% by weight of said recurring long-chain ester units and from about 20% to about 95% by weight of said recurring short-chain ester units, or from about 10% to about 75% by weight of recurring long-chain ester units and from about 25% to about 90% by weight of recurring short-chain ester units.

As used herein, "long-chain ester units" refers to the products resulting from the reaction of long-chain diols and dicarboxylic acids. Suitable long chain diols are poly (alkylene ether) diols having a number average molecular weight of about 400-6000, or about 600-3000 containing terminal hydroxyl groups, including but not limited to poly (tetramethylene ether) diol, poly (trimethylene ether) diol, polypropylene oxide diol, polyethylene oxide diol, copolymers of the above poly (alkylene ether) diols, and block copolymers such as ethylene oxide capped poly (propylene oxide) diol. The long-chain diol may also be a mixture of two or more of the above diols.

As used herein, "short-chain ester units" refers to the products resulting from the reaction of a low molecular weight diol or ester-forming derivative thereof with a dicarboxylic acid. Suitable low molecular weight diols have a number average molecular weight of equal to or less than about 250 (or about 10 to 250, or about 20 to 150, or about 50 to 100), and include, but are not limited to, aliphatic dihydroxy compounds, alicyclic dihydroxy compounds, and aromatic dihydroxy compounds (including bisphenols). In one embodiment, the low molecular weight diol used is a dihydroxy compound containing about 2 to 15 carbon atoms, such as ethylene glycol, propylene glycol, isobutylene glycol, 1, 4-butanediol, 1, 4-pentanediol, 2-dimethylpropanediol, 1, 6-hexanediol, 1, 10-decanediol, dihydroxycyclohexane, cyclohexanedimethanol, resorcinol, hydroquinone, 1, 5-dihydroxynaphthalene, and the like. In another embodiment, the low molecular weight diol used is a dihydroxy compound containing about 2 to 8 carbon atoms. In another embodiment, the low molecular weight diol used is 1, 4-butanediol. Suitable bisphenols for use herein include bis (p-hydroxy) biphenyl, bis (p-hydroxyphenyl) methane and bis (p-hydroxyphenyl) propane. The ester-forming derivative of a low-molecular-weight diol suitable for use herein means an ester-forming derivative derived from the above-mentioned low-molecular-weight diol, for example, an ester-forming derivative of ethylene glycol (e.g., ethylene oxide or ethylene carbonate) or an ester-forming derivative of resorcinol (e.g., resorcinol diacetate). Here, the definition of the number average molecular weight is applicable only to the low molecular weight diol, and thus, the diol ester-forming derivative having a number average molecular weight of more than about 250 is also applicable as long as the corresponding low molecular weight diol has a number average molecular weight of about 250 or less.

The "dicarboxylic acid" reacted with the above-mentioned long-chain diol or low-molecular weight diol is an aliphatic, alicyclic or aromatic dicarboxylic acid having a low molecular weight (i.e., a number average molecular weight of about 300 or less, or about 10 to 300, or about 30 to 200, or about 50 to 100). Also, dicarboxylic acids suitable for use herein include functional equivalents of dicarboxylic acids. In forming the copolyetherester polymer, the dicarboxylic acid functional equivalent reacts with the long chain diol or low molecular weight diol described above in essentially the same manner as the dicarboxylic acid. Suitable functional equivalents of dicarboxylic acids include esters and ester-forming derivatives of dicarboxylic acids, such as acid halides and anhydrides. The number average molecular weight is defined herein only with respect to the corresponding dicarboxylic acid and not a functional equivalent thereof (e.g., an ester or ester-forming derivative of a dicarboxylic acid). Thus, dicarboxylic acid functional equivalents having a number average molecular weight greater than about 300 are also suitable for use herein, as long as the corresponding dicarboxylic acid has a number average molecular weight of equal to or less than about 300. In addition, the dicarboxylic acids suitable for use herein may also contain any substituent or combination of substituents that do not substantially interfere with the formation of the copolyetherester polymer and its use in the composition.

Copolyetheresters suitable for use in the abrasive filaments disclosed herein can be prepared by methods known to those skilled in the art, for example, using conventional transesterification reactions.

According to the invention, the copolyetheresters suitable for the invention have a melt index not particularly limited, preferably ranging from 1 to 10g/10min (measured according to ISO1133-1:2001 standard method).

Thermoplastic elastomers suitable for use in the present invention are commercially available, for example, under the trade name of E.I. Du Pont de Nemours and Company (hereinafter "DuPont"), U.S.A

Copolyetheresters of (A), available from the Dow chemical company under the trade name Pellethane^TMThermoplastic elastomer of (2), under the trade name of basf

Of (A) or available from Bayer under the trade name of

The polyurethane elastomer of (1).

In one embodiment of the present invention, the abrasive filament comprises about 1 to 10 wt% thermoplastic elastomer, or about 3 to 7 wt% thermoplastic elastomer, wherein the wt% is based on the total weight of the abrasive filament.

(d) Other additivesAdditive agent

In the present invention, the abrasive filament further comprises from about 0.1 to about 35 weight percent of other additives selected from the group consisting of abrasive particles, compatibilizers, hydrolysis resistance agents, and mixtures thereof, wherein the weight percent is based on the total weight of the abrasive filament.

The abrasive particles may be conventionally used in the art for making abrasive filaments and may be selected from the group consisting of silicon carbide, aluminum oxide, titanium diboride, zirconia, boron carbide, cerium oxide, aluminum silicate, boron nitride, silica, diamond, garnet, pumice, mica, corundum, quartz, and mixtures thereof, preferably silicon carbide, aluminum oxide, or diamond, more preferably silicon carbide.

According to the present invention, the abrasive particles may be used in only one kind, or may be used in combination of two or more kinds. According to the present invention, the abrasive particles generally have a particle size of about 30 to 3000 mesh, preferably about 40 to 2000 mesh, and further preferably about 40 to 1000 mesh, but are not limited thereto in some cases. According to the present invention, the shape of the abrasive particles is not limited at all, and may be spherical, polygonal, irregular block-like, or the like, as long as the particle size satisfies the specification of the present invention. The abrasive particles may be surface treated (e.g., silane coupling agent treatment) according to methods known in the art to improve their binding or compatibility with the polymer, as desired. These techniques will be apparent to those skilled in the art and will not be described in detail herein.

Abrasive particles suitable for use in the present invention may also be obtained from commercially available sources, such as silicon carbide from U.S. abrasive products, alumina and silicon carbide from Suzhou Kema materials, or alumina and silicon carbide from Tianyue Crystal materials, Inc.

In one embodiment of the present invention, the abrasive filament comprises 0 to 35 wt% abrasive particles, wherein the wt% is based on the total weight of the abrasive filament.

In yet another embodiment of the present invention, the abrasive particles in the abrasive filament are silicon carbide.

The compatibilizing agent may be one that is known in the art to facilitate polyamide 610 and polyethylene in the manufacture of abrasive filaments. The compatibilizing agent suitable for the present invention may be an ethylene copolymer or a polyolefin modified with an ethylenically unsaturated carboxylic acid and/or an ethylenically unsaturated carboxylic acid derivative (hereinafter also referred to as modified polyolefin); examples of the ethylene copolymer include a copolymer or ionomer of ethylene and an ethylenically unsaturated carboxylic acid and/or an ethylenically unsaturated carboxylic acid derivative, and examples thereof are selected from the group consisting of an ethylene-methacrylic acid-acrylate ionomer, an ethylene-butyl acrylate-carbonyl copolymer, and a mixture thereof.

According to the present invention, the compatibilizing agent may be used alone or in combination of two or more.

Compatibilizers suitable for the present invention may be obtained from commercial sources, for example, from DuPont under the trade name DuPont

Or

Of (D) an ethylene copolymer of (D), under the trade name DuPont

Or

Commercially available modified polyolefins, ethylene copolymers or modified polyolefins available from Schulman, Switzerland under the trade name Polyfort EVA 00607ME Schwarz and Czerland Silon under the trade name EVA Tab Bond 3042, ethylene copolymers or modified polyolefins available from Asahi in Japan under the trade name RF7830, ethylene copolymers or modified polyolefins available from Nippon Yornia under the trade name WSVA3020, ethylene copolymers or modified polyolefins available from Nippon Sumitomo chemical under the trade name SWA230, ethylene copolymers or modified polyolefins available from Toyo Co in Japan under the trade name L-3388, ethylene copolymers or modified polyolefins available from Toyo chemical, and PRIMCOR under the trade name PRIMCOR available from Dow chemical^TM3004 and 4608 ethylene copolymers or modified polyolefins, and available from exxon-Mobil under the trade name Escor^TMEthylene copolymers or modified polyolefins of EAA 5200, and the like.

In one embodiment of the present invention, the abrasive filament comprises about 0.01 to 1 wt% compatibilizing agent, wherein the wt% is based on the total weight of the abrasive filament.

In yet another embodiment of the present invention, the compatibilizing agent in the abrasive filament is selected from the group consisting of ethylene-methacrylic acid-acrylate ionomers, ethylene-butyl acrylate-carbonyl copolymers, or mixtures thereof.

The abrasive filaments of the present invention further comprise a hydrolysis resistance agent for inhibiting hydrolysis of the polyamide 610, and suitable hydrolysis resistance agents of the present invention may be selected from the group consisting of polycarbodiimide, isocyanates, epoxy compounds, and mixtures thereof.

In one embodiment of the present invention, the abrasive filament comprises about 0.01 to 1 wt% hydrolysis resistant agent, wherein the wt% is based on the total weight of the abrasive filament.

In yet another embodiment of the present invention, the hydrolysis resistant agent in the abrasive filament is a polycarbodiimide, such as a polyaromatic carbodiimide, poly [ nitrilomethane tetraazao [2,4, 6-tris (1-methylethyl) -1, 3-phenylene ], or poly-1, 3, 5-triisopropyl-phenylene-2, 4-carbodiimide.

Hydrolysis resistant agents suitable for the present invention are commercially available, for example poly-1, 3, 5-triisopropyl-phenylene-2, 4-carbodiimide available under the trade name Stabilizer from RASCHIG (RASCHIG) ltd.

In accordance with the present invention, the abrasive filaments may also contain various additives conventionally used in the art of making abrasive filaments, such as acid absorbers, colorants (such as pigments and dyes, etc.), antioxidants, tackifiers, and lubricants (such as graphite, polytetrafluoroethylene), etc., in amounts conventionally used in the art, so long as the incorporation of such additives or the specific amounts thereof do not adversely affect the achievement of the intended effects of the present invention.

In the abrasive filaments of the present invention, the weight ratio of polyethylene to thermoplastic elastomer is about 0.3 to 4, or about 0.4 to 3, or about 0.4 to 2.5.

In one embodiment of the invention, the polyethylene is a linear low density polyethylene, the thermoplastic elastomer is a copolyetherester, and the weight ratio of the linear low density polyethylene to the copolyetherester is about 0.4 to 3.

According to the present invention, the abrasive filament generally has a diameter of about 0.2 to 5mm, preferably about 0.4 to 3mm, but is sometimes not limited thereto according to practical needs.

According to the invention, the abrasive filaments can be present in the form of (long, short) monofilaments or (long, short) tows, which are independent of one another. Alternatively, bonding sites such as localized bonds or entanglements may be present between the abrasive filaments, in which case the abrasive filaments are typically in the form of a entangled web or nonwoven of fibers.

Abrasive filament manufacture

According to the present invention, the abrasive filament may be made by a manufacturing method comprising the steps of:

(i) mixing about 55-95 wt% polyamide 610, about 1-10 wt% polyethylene, about 1-10 wt% thermoplastic elastomer, and about 0.1-35 wt% of other additives selected from the group consisting of abrasive particles, compatibilizers, hydrolysis resistance agents, and mixtures thereof to provide an abrasive composition; and

(ii) melt spinning the abrasive composition to obtain an abrasive filament;

wherein the weight% is based on the total weight of the abrasive composition.

According to the present invention, there is no particular limitation on the specific embodiment of step (i), and any technique in the art that can mix the polymer raw material (comprising polyamide 610, polyethylene, and thermoplastic elastomer) and other additives (such as abrasive particles, compatibilizers, anti-hydrolysis agents, and other additives used as needed) to be uniform in the amount ratio specified herein may be used. Among them, a technique using a screw extruder is preferable, and for example, but not limited to, a technique in which a polymer raw material and other additives are added simultaneously and/or sequentially in an amount specified in the present invention to one or more feed ports of a screw extruder and mixed until uniform. For example, the polyamide 610, the polyethylene, and the thermoplastic elastomer may be previously mixed in the amounts specified in the present invention to be uniform to obtain a polymer raw material, the compatibilizer, and the hydrolysis-resistant agent may be further mixed to be uniform, and then the abrasive particles in the amounts specified in the present invention may be added to the obtained mixture and mixed to be uniform.

According to the present invention, the specific embodiment of step (ii) is not particularly limited, and any technique in the art that can melt-spin the abrasive composition obtained in step (i) can be used. Among them, a technique using a screw extruder is preferable, and for example, but not limited to, a technique of melting the abrasive composition at a certain temperature using a screw extruder and then extruding the melt through a spinneret orifice to form a filament. The filaments are further drawn to a predetermined diameter after or during extrusion, as desired, in any manner conventionally known in the art.

According to the present invention, step (i) and step (ii) may be performed in the same step, or may be performed separately as separate steps. As an example of this being done in one and the same step, the polymer raw material and the further additives are added simultaneously and/or successively in the amounts specified according to the invention to one or more feed openings of a screw extruder, melt-mixed until homogeneous and the melt obtained is then extruded through a spinneret orifice to form filaments. As an example of the separate process, for example, an abrasive composition is prepared and then melt-spun using the abrasive composition as a raw material. According to the invention, it is preferred that step (i) and step (ii) are carried out in the same step.

According to the present invention, in order to carry out said steps (i) and (ii), it is preferred to use a screw extruder (in particular a twin-screw extruder). Mixing/melt spinning techniques using screw extruders are widely known in the art and will not be described in detail herein.

According to the present invention, the melt temperature of the abrasive composition is generally about 230 ℃ to 300 ℃, preferably about 240 ℃ to 280 ℃ when the melt spinning of step (ii) is performed, but may be set according to the actual conditions of the melt spinning and the specific melting point or melting temperature of the abrasive composition, and is not limited to the range specified herein.

In the present invention, the acid resistance of the abrasive filament is characterized by a relative viscosity loss rate. The relative viscosity loss rate is the ratio of the loss value of the relative viscosity of the abrasive wire after the abrasive wire is treated by the acid solution to the relative viscosity of the abrasive wire before the acid treatment, and the larger the relative viscosity loss rate is, the more the abrasive wire is degraded in the acid solution during the treatment process is, and the poorer the acid resistance is. As previously mentioned, it is desirable to obtain abrasive filaments having improved acid resistance, and in the present invention, the inventors have unexpectedly discovered that abrasive filaments made by replacing a portion of the polyethylene with a thermoplastic elastomer, i.e., by adding a weight ratio of about 0.3 to about 4 of polyethylene to the polyamide 610, and a thermoplastic elastomer, have unexpectedly improved acid resistance. Treatment of the corresponding abrasive filament with an acid having a PH of about 1 showed an improved acid resistance, as compared to an abrasive filament comprising the same composition of polyamide 610 and polyethylene but not comprising a thermoplastic elastomer (a relative viscosity loss of 29.5%), which had a relative viscosity loss of only 15.7% to 21.9%.

The present inventors have also surprisingly found that replacing a portion of the polyethylene with a thermoplastic elastomer, i.e., adding to the polyamide 610 abrasive filaments made from polyethylene and a thermoplastic elastomer in a weight ratio of about 0.3 to 4, also has unexpectedly improved abrasion resistance. In the invention, the wear resistance of the abrasive wire is characterized by the weight loss rate, wherein the weight loss rate is the ratio of the loss value of the weight of the abrasive wire after the metal rod is ground by the abrasive wire to the weight of the abrasive wire before grinding, and the larger the weight loss rate is, the poorer the wear resistance of the abrasive wire is. The abrasive filaments of the present invention have a weight loss ratio of only 0.57% to 0.72% and exhibit improved abrasion resistance, as compared to abrasive filaments comprising the same composition of polyamide 610 and polyethylene but not comprising a thermoplastic elastomer (weight loss ratio of 0.76%). The inventors have further found that even when the abrasion resistance test is performed under acidic conditions, i.e., after the abrasive filament is treated with an acidic solution, the abrasive filament of the present invention exhibits improved abrasion resistance as compared to an abrasive filament comprising polyamide 610 and polyethylene of the same composition but not comprising a thermoplastic elastomer (weight loss rate of 1.33%), with a weight loss rate of only 1.08% to 1.31%.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. Accordingly, the following examples are illustrative only and are not intended to limit the disclosure in any way.

Examples

The abbreviation "E" stands for "examples" and "CE" for "comparative examples", the numbers following which indicate in which example the composition was prepared. Examples and comparative examples were both prepared and tested in a similar manner.

Material

Polyamide 610: polyhexamethylene sebacamide having a melting point of about 220 ℃ and a relative viscosity of about 2.91, under the trade name

Obtained from dupont xingda (tin-free) monofilaments limited;

polyethylene: under the trade name ExxonMobil^TMLLDPE LL 1002YB is a linear low density polyethylene from Exxon Mobil having a melt index of about 2.0g/10 min;

thermoplastic elastomer: under the trade name of

Copolyetheresters available from dupont;

abrasive particles: 60 mesh size silicon carbide available from U.S. abrasive tools, inc;

compatibilizer-1: under the trade name of

Ethylene-methacrylic acid-acrylate ionomers available from dupont, where methacrylic acid is partially neutralized with zinc ions;

compatibilizer-2: under the trade name of

Ethylene-butyl acrylate-carbonyl copolymer available from dupont;

hydrolysis resistance agent: poly-1, 3, 5-triisopropyl-phenylene-2, 4-carbodiimide available from RASCHIG (RASCHIG) ltd under the trade name Stabilizer.

Preparation of abrasive filaments for E1-E4 and CE1-CE7

Polyamide 610, polyethylene, thermoplastic elastomer, compatibilizer, and hydrolysis resistant agent were mixed to be uniform according to the kinds and amounts shown in table 1. Then, the obtained mixture was fed into the main feeding port of a twin-screw extruder (Nanjing Ruiya extrusion machinery manufacturing Co., Ltd., screw diameter 35mm, aspect ratio 40, screw rotation speed 120-. The extrudate was immediately cooled to a raw filament in water at a temperature of 10 ℃. The as-spun filaments were passed through a slow roll (8.1MPM), a hot water bath (75 ℃ C.), a first fast roll (20.3MPM), an annealing furnace (250 ℃ C.), and a second fast roll (19.9MPM) in this order, thereby obtaining abrasive filaments having a diameter of 1.85mm for examples E1-E4 and comparative examples CE1-CE 7.

Test method

1. Acid treatment

There are two methods of acid treating abrasive filaments in the present invention: (1) cutting the abrasive filament to a length of about 50cm and then soaking in a sulfuric acid solution having a concentration of 0.3 wt% and a PH of about 1; soaking for 264 hours at the temperature of 85 ℃, and then taking out; then rinsed with a large amount of pure water for about 10 minutes and soaked for about 2 hours, and then taken out to be dried. (2) Cutting the abrasive wire into a length of about 50cm, and then soaking in a sulfuric acid solution with a concentration of 30 wt% and a pH value of less than 1; soaking for 24 hours at the temperature of 85 ℃, and then taking out; then rinsed with a large amount of pure water for about 10 minutes and soaked for about 2 hours, and then taken out to be dried.

2. Rate of weight loss

A certain amount of abrasive filaments was taken, cut to a length of about 35mm, and the weight m thereof was measured₀Then evenly dividing the material into four parts by weight, fixing each part of abrasive wire on four clamping heads at intervals of 90 degrees on the same chuck by using knobs, and enabling the abrasive wire to axially moveThe direction is vertical to the plane direction of the chuck, and the exposed length of the chuck is about 31.75 mm; fixing a copper rod with the diameter of about 8mm above the chuck, wherein the axial direction of the copper rod is parallel to the plane direction of the chuck, and the vertical distance between the copper rod and the chuck is about 24 mm; rotating the chuck at a rotational frequency of about 14.3Hz so that the four tows grind the copper bar at the same point; after about 30 minutes the chuck was stopped, four tows were removed and their total weight m was measured.

The weight loss (Δ m%) of the abrasive filament is calculated by the following formula:

Δm％＝[(m₀-m)/m ₀]x 100

wherein m is the weight of the abrasive filament after grinding; m is₀Is the weight of the abrasive filament prior to grinding.

After the abrasive wire is treated by the above-described acid treatment method, the weight loss of the acid-treated abrasive wire is measured by the above-described method for measuring weight loss. The weight loss rate-1 is the weight loss rate of the abrasive filament treated according to the method (1).

If the abrasive filaments are completely broken after grinding according to the above method for measuring the weight loss rate, the total weight is discarded and not measured, and the value of the weight loss rate is recorded as "broken".

3. Rate of loss of relative viscosity

About 0.25 grams of abrasive filament was cut to a length of about 1-3mm and dissolved in about 20ml of a sulfuric acid solution having a concentration of about 96% by weight using a viscometer (ViscoSystem)^TMAVS 370, SI analytical GmbH) measures the time t for which it flows through the viscometer's manifold at a temperature of 25 ℃; about 20ml of a sulfuric acid solution having a concentration of about 96% by weight are again measured and the time t during which it flows through the branches of the viscometer at a temperature of 25 ℃ is measured with the viscometer₀(ii) a t and t₀Is the relative viscosity value RV of the abrasive wire₀。

After each treatment of the abrasive filament with acid, about 0.25 grams of abrasive filament was measured for relative viscosity RV using the above described measurement₀The relative viscosity value RV of the acid treated abrasive filament is measured.

The relative viscosity loss ratio (. DELTA.RV%) was calculated by the following formula:

ΔRV％＝[(RV-RV₀)/RV ₀]x 100

wherein RV is the relative viscosity of the acid treated abrasive filament; RV (direction of rotation)₀Is the relative viscosity of the abrasive filament prior to treatment with acid. The relative viscosity loss ratio-1 is the relative viscosity loss ratio after the treatment according to the acid treatment of the type (1); the relative viscosity loss ratio-2 is the relative viscosity loss ratio after the treatment according to the acid treatment of the type (2). If the weight loss rate of the abrasive filament of a particular example or comparative example is "off," i.e., the abrasive filament breaks throughout after grinding, it is discarded and its relative viscosity is no longer measured, and its relative viscosity loss rate is recorded as "none".

TABLE 1

“^a"indicate that the abrasive filament was discarded after all breaks after grinding, and the value of the weight loss rate was recorded as" broken "; "^bThe "indicated" indicates that the abrasive filaments were discarded after all breaks had occurred after grinding and no relative viscosity loss was tested.

From the results of Table 1, the following description is evident.

Comparison of the weight loss rate data for E1-E3 and CE1-CE5 shows that: the abrasive filaments of E1-E3 of the present invention had a weight loss ratio of only 0.57% to 0.72% as compared to the abrasive filaments of CE1 comprising only polyamide 610 and abrasive particles (weight loss ratio of 0.77%) and the abrasive filaments of CE2 comprising polyamide 610 and polyethylene of the same composition but not comprising a thermoplastic elastomer (weight loss ratio of 0.76%); replacement of a portion of the polyethylene with a thermoplastic elastomer, i.e., addition of a weight ratio of about 7:3, 5:5, or 3:7 of polyethylene to the polyamide 610 with a thermoplastic elastomer, produced abrasive filaments with unexpectedly improved abrasion resistance. When the weight of polyethylene and thermoplastic elastomer added to polyamide 610 is 0, 1: 9. or 2:8, the obtained abrasive wire of CE3-CE5 was broken in the grinding process for measuring the weight loss rate, indicating that the wear resistance was poor.

Comparison of the weight loss rate-1 data for E1-E3 and CE1-CE5 shows that: even when the abrasion resistance test was performed after the above abrasive filaments were treated under acidic conditions, i.e., by the (1) st acid treatment, the abrasive filaments of E1-E3 according to the present invention exhibited improved abrasion resistance, as compared to the abrasive filaments of CE1 (weight loss rate-1 of 3.26%) and the abrasive filaments of CE2 (weight loss rate-1 of 1.33%). The abrasive filaments of CE3-CE5, on the other hand, all broke during the grinding process to measure weight loss-1, indicating that they also had poor wear resistance after acid treatment.

Comparison of the relative viscosity loss rate-1 data for E1-E3 and CE1-CE5 indicates that: the abrasive filaments treated by the acid treatment method (1) caused a loss of relative viscosity, and the acid-treated abrasive filaments of the present invention E1-E3 exhibited an improved acid resistance, with a loss of relative viscosity of only 15.7% to 21.9% from 1, as compared to the abrasive filaments of CE1 (34.5% loss of relative viscosity-1) and CE2 (29.5% loss of relative viscosity-1).

Comparison of the relative viscosity loss rate-2 data for E1-E3 and CE1-CE5 indicates that: the acid treatment of the abrasive filaments according to method (2) caused a loss of relative viscosity, and the acid treatment of the abrasive filaments according to the invention, E1-E3, resulted in a loss of relative viscosity of only 53.8% to 56.2% compared to the abrasive filaments according to CE1 (loss of relative viscosity-2 of 59.4%) and CE2 (loss of relative viscosity of-2 of 57.2%), indicating that the abrasive filaments according to the invention exhibit improved acid resistance even when treated with sulfuric acid at concentrations up to about 30% by weight.

Comparison of the weight loss rate data for E4 and CE6-CE7 shows that: the abrasive filament of CE6 (weight loss 0.44%) comprising the same components of polyamide 610 and polyethylene but no thermoplastic elastomer had a weight loss of only 0.32% for the abrasive filament of E4 of the present invention; abrasive filaments made by substituting a portion of the polyethylene with a thermoplastic elastomer, i.e., adding a weight ratio of about 3:7 of polyethylene to thermoplastic elastomer to polyamide 610, had unexpectedly improved abrasion resistance. When the thermoplastic elastomer added to the polyamide 610 completely replaced the polyethylene, the abrasive filament of CE7 produced all broke during grinding to measure weight loss rate, indicating poor abrasion resistance.

Comparison of the weight loss rate-1 data for E4 and CE6-CE7 shows that: even when the abrasion resistance test was performed after the above abrasive filament was treated under acidic conditions, i.e., by the (1) st acid treatment, the abrasive filament of E4 of the present invention showed an improved abrasion resistance with a weight loss rate of-1 of only 4.21% as compared with the abrasive filament of CE6 (weight loss rate of-1 of 5.13%). When the thermoplastic elastomer added to the polyamide 610 completely replaced the polyethylene, the resulting abrasive filament of CE7 broke completely during grinding to determine the weight loss rate-1, indicating that it also had poor abrasion resistance after acid treatment.

Comparison of the relative viscosity loss rate-1 data for E4 and CE6-CE7 shows that: the treatment of the abrasive filament with the (1) acid treatment method resulted in a loss of relative viscosity, and the acid-treated relative viscosity loss rate-1 of the abrasive filament of E4 of the present invention was only 20.9% compared to the abrasive filament of CE6 (44.1% for relative viscosity loss rate-1), showing improved acid resistance.

Comparison of the relative viscosity loss rate-2 data for E4 and CE6-CE7 shows that: the treatment of the abrasive filaments with the (1) acid treatment resulted in a loss of relative viscosity, and the acid treated relative viscosity loss of the abrasive filaments of the invention, E4, was only 55.5% compared to the CE6 abrasive filaments (59.6% relative viscosity loss-2), indicating that the abrasive filaments of the invention exhibited improved acid resistance even when treated with sulfuric acid at concentrations up to about 30 wt.%

In one embodiment of the present invention, the abrasive filament comprises:

(a) about 55 to about 95 weight percent of polyamide 610;

(b) about 1-10 wt% of a linear low density polyethylene;

(c) about 1-10 wt% of a copolyetherester; and

wherein the weight% is based on the total weight of the abrasive filament.

While the invention has been illustrated and described in typical embodiments, it is not intended to be limited to the details shown, since various modifications and substitutions are possible without departing in any way from the spirit of the present invention. Thus, modifications and equivalents of the invention herein disclosed may occur to persons skilled in the art using no more than routine experimentation, and all such modifications and equivalents are believed to be within the spirit and scope of the invention as defined by the following claims.

Claims

1. An abrasive filament, comprising:

(a) 55-95% by weight of polyamide 610;

(b)1-10 wt% polyethylene;

(c)1-10 wt% of a thermoplastic elastomer; and

(d) 0.1-35% by weight of other additives selected from abrasive particles, compatibilizers, hydrolysis resistance agents, and mixtures thereof;

wherein the weight% is based on the total weight of the abrasive filament;

the weight ratio of the polyethylene to the thermoplastic elastomer is 0.4-2.5, and the thermoplastic elastomer is copolyether ester

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2. The abrasive filament according to claim 1, wherein said polyethylene is selected from the group consisting of linear low density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, ultra low density polyethylene, and mixtures thereof.

3. The abrasive wire of claim 1 wherein said abrasive particles are selected from the group consisting of silicon carbide, aluminum oxide, titanium diboride, zirconia, boron carbide, cerium oxide, aluminum silicate, boron nitride, silica, diamond, garnet, pumice, mica, corundum, quartz, and mixtures thereof.

4. The abrasive wire of claim 1 wherein said compatibilizing agent is selected from the group consisting of ethylene copolymers, polyolefins modified with ethylenically unsaturated carboxylic acids and/or ethylenically unsaturated carboxylic acid derivatives, and mixtures thereof; the hydrolysis resistant agent is selected from the group consisting of polycarbodiimides, isocyanates, epoxies, and mixtures thereof.

5. The abrasive wire of claim 1 wherein said compatibilizing agent is selected from the group consisting of ethylene-methacrylic acid-acrylate copolymers, ethylene-butyl acrylate-carboxylic acid copolymers, and mixtures thereof; the hydrolysis resistant agent is selected from the group consisting of polyaromatic carbodiimides, poly [ nitrilomethane tetraazao [2,4, 6-tris (1-methylethyl) -1, 3-phenylene ], poly-1, 3, 5-triisopropyl-phenylene-2, 4-carbodiimides, and mixtures thereof.

6. The abrasive filament according to claim 1, wherein said abrasive filament is a monofilament having a diameter in the range of 0.2-5 mm.

7. A method of making the abrasive filament of any one of claims 1 to 6 comprising the steps of:

i. mixing 55-95 wt% of polyamide 610, 1-10 wt% of polyethylene, 1-10 wt% of thermoplastic elastomer, and 0.1-35 wt% of other additives selected from abrasive particles, compatibilizers, hydrolysis resistance agents, and mixtures thereof to obtain an abrasive composition; and

melt spinning the abrasive composition to provide an abrasive filament;

wherein the weight% is based on the total weight of the abrasive composition;

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