KR20210100899A - POLYESTER-BASED CARBON BLACK MASTER BATCH COMPOSITION AND Preparation method THEREOF - Google Patents

Abstract

The present invention relates to a polyester-based carbon black masterbatch composition including a polyester resin, carbon black having a surface pH of 3 to 7, and an aliphatic carbodiimide, and a method for manufacturing the same. According to the present invention, a carbon black masterbatch having relatively high viscosity can be manufactured, and when a product is produced by applying the carbon black masterbatch through the same, a product having superior physical properties can be manufactured.

Description

Polyester-based carbon black masterbatch composition and its manufacturing method {POLYESTER-BASED CARBON BLACK MASTER BATCH COMPOSITION AND Preparation method THEREOF}

The present invention relates to a polyester-based carbon black masterbatch composition and a method for preparing the same, and more particularly, to a polyester-based carbon black masterbatch composition with improved hydrolysis resistance and a method for preparing the same.

It is generally practiced to mix carbon-based particles such as graphite or carbon black for the purpose of imparting conductivity to the polyester resin or for the purpose of coloring.

However, since carbon black is very difficult to knead, when the amount of carbon black added is increased, it is difficult to melt the resin composition due to poor dispersion of carbon black, or flow marks are generated on the appearance of the molded article, There is a problem in that carbon black is exposed on the surface of the molded article due to poor dispersion, and peel strength is lowered.

On the other hand, conventionally, when coloring a thermoplastic resin in black, the method of mix|blending carbon black with a resin composition, melt-kneading this with an extruder, extruding, cutting|disconnecting and making into pellet form is widely performed. However, in this method, when the powder of carbon black is blended into the resin composition as it is, contamination of the working environment due to fine powder, handling problems, occurrence of non-uniformity of carbon black due to classification or agglomeration, etc., and color change with respect to subsequent lots There is a problem such as remaining or color mixing.

Accordingly, there is known a method of preparing a masterbatch in which carbon black is dispersed in a high concentration in a resin in advance and using this to color the resin. Since this coloring method does not scatter carbon black and has excellent handleability, it has become a mainstream method for coloring resins at present.

A polyester-based carbon black masterbatch is prepared through compounding by adding carbon black to a polyester-based resin. In the case of carbon black, since it exists in powder form, it is difficult to dry, so there is no separate moisture management. In general, carbon black has a high moisture content due to its large surface area and affinity for moisture. Due to these characteristics, when used in the manufacture of carbon black masterbatch, hydrolysis of the base resin occurs during compounding at a high temperature. For example, when a base chip having an intrinsic viscosity of 0.8 undergoes a compounding process, a problem occurs in that the intrinsic viscosity is reduced to a level of 0.3. In particular, polyester resins are sensitive to hydrolysis at temperatures higher than the glass transition temperature. The susceptibility to hydrolysis of the polyester resin is a property of the polyester that is deteriorated by hydrolysis under moisture conditions, and can be confirmed, for example, by a decrease in the IV value. As such, polyester-based resins are very vulnerable to hydrolysis, and generally, a significant decrease in molecular weight occurs during the manufacture of carbon black masterbatch. Therefore, when the carbon black masterbatch is used in the production of yarn, it has a profound effect on the reduction of the physical properties of the product.

Accordingly, various attempts have been made to improve the hydrolysis resistance of the polyester-based carbon black masterbatch through the mixing of a hydrolysis stabilizer.

Korean Patent Publication No. 2003-0090516 discloses a technique of using polycarbodiimide as a hydrolysis stabilizer, but this polycarbodiimide has a yellowing problem during the process, and its use is limited to clothing fibers, It is difficult to apply to applications where color is seriously considered, such as films and sheets, and since viscosity increases during extrusion, the extrusion process is unstable and difficult to control.

German Patent No. 1048068 discloses the use of copper salts of organic carboxylic acids as hydrolysis stabilizers. US 2007/0238816 discloses the use of epoxidized fatty acid alkyl esters and epoxidized fatty acid glycerides as hydrolysis stabilizers in polyester compositions.

However, these prior arts do not recognize the hydrolysis resistance of the polyester-based carbon black masterbatch, and do not sufficiently improve the hydrolysis resistance of the polyester resin, so improvement is required.

The present invention is to solve the problems of the prior art described above, and one object of the present invention is to provide a polyester-based carbon black masterbatch composition that can more continuously maintain physical properties such as mechanical strength due to excellent hydrolysis resistance. will provide

Another object of the present invention is a polyester-based carbon black masterbatch composition capable of improving the physical properties of a product when the carbon black masterbatch is used for yarn production by solving a serious problem of molecular weight reduction in the production of carbon black masterbatch, and a composition thereof To provide a manufacturing method.

One aspect of the present invention for achieving the above object is,

It relates to a polyester-based carbon black masterbatch composition comprising a polyester resin, carbon black having a surface pH of 3 to 7, and an aliphatic carbodiimide represented by the following formula (1):

[Formula 1]

R ₁ -N=C=NR ₂

In the above formula, R ₁ and R ₂ are each independently an aromatic group having 5 to 30 carbon atoms, an alicyclic group having 5 to 20 carbon atoms, or a bulky alkyl group having 5 to 30 carbon atoms.

Specific examples of the aliphatic carbodiimide compound include a compound represented by the following formula (2).

[Formula 2]

In the above formula, R ₃ , R ₄ , R ₅ , and R ₆ are each independently a hydrogen atom, a linear or branched alkyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 8 carbon atoms.

In the present invention, the carbon black may have an average particle size of 10 to 200 nm and a specific surface area of 160 to 340 m 2 /g.

The masterbatch composition has a moisture content of 4 or more, and an intrinsic viscosity of 0.3 to 0.6. In the present invention, the polyester resin is polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polytrimethylene terephthalate, bibenzene-modified polyethylene terephthalate (bibenzene-modified polyethylene terephthalate), bibenzene-modified It may be one selected from the group consisting of polybutylene terephthalate, bibenzene-modified polyethylene naphthalate, or a mixture thereof.

The composition of the present invention may contain 1 to 4% by weight of the aliphatic carbodiimide compound of Formula 1 based on 100% by weight of the mixture of the polyester resin and carbon black.

One aspect of the present invention for achieving the above object is,

It relates to a method for producing a polyester-based carbon black masterbatch, comprising mixing a polyester resin, carbon black having a surface pH of 3 to 8, and an aliphatic carbodiimide represented by the following formula (1).

According to the present invention, when producing a polyester-based carbon black masterbatch, a masterbatch having a relatively high viscosity can be prepared by adding a hydrolysis inhibitor, and through this, when a product is produced by applying the carbon black masterbatch, It is possible to manufacture a product having excellent physical properties.

In addition, according to the present invention, it is possible to provide a carbon black masterbatch for coloring that is easy to mass-produce and does not cause appearance defects in colored yarns or molded articles.

Hereinafter, the present invention will be described in more detail.

As used herein, the terms "comprises," "comprising," specify the presence of the stated feature, element, step or component, and the presence or addition of one or more other features, elements, steps, components. It is not intended to exclude

One aspect of the present invention relates to a polyester-based carbon black masterbatch composition comprising a polyester resin, carbon black having a surface pH of 3 to 7, and an aliphatic carbodiimide represented by the following formula (1):

[Formula 1]

R ₁ -N=C=NR ₂

In the above formula, R ₁ and R ₂ are each independently an aromatic group having 5 to 30 carbon atoms, an alicyclic group having 5 to 20 carbon atoms, or a bulky alkyl group having 5 to 30 carbon atoms.

The aliphatic carbodiimide compound may include, but is not limited to, a compound represented by Formula 2 below.

[Formula 2]

In the above formula, R ₃ , R ₄ , R ₅ , and R ₆ are each independently a hydrogen atom, a linear or branched alkyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 8 carbon atoms.

Hydrolysis of the polyester-based carbon black masterbatch caused by the high moisture content of carbon black causes serious deterioration in physical properties of the product through reduction of molecular weight, and a technique for improving this is not known. The present invention prevents hydrolysis by adding a carbodiimide-based hydrolysis inhibitor as shown in Formula 1 when preparing a carbon black masterbatch to remove water that induces hydrolysis and at the same time removes a carboxyl group that promotes hydrolysis. . Carbodiimide of Formula 1 can react with water to remove water as shown in the following reaction formula, and at the same time react with a carboxyl group, which is the terminal of the polyester-based resin, to prevent hydrolysis through terminal removal.

[Scheme 1]

The amount of the aliphatic carbodiimide compound used in preparing the carbon black masterbatch is 1 to 4% by weight, preferably 2 to 3%, based on 100% by weight of the mixture of the polyester-based resin and carbon black. When the content of the aliphatic carbodiimide compound is less than 1% by weight, it is difficult to obtain a sufficient effect of preventing hydrolysis, and when the content exceeds 5%, there is a problem of altering the properties of the product itself.

The carbon black masterbatch composition of the present invention has a water content of 4 or more and an intrinsic viscosity of 0.3 to 0.6.

polyester resin

The polyester resin is an aromatic polyester resin, and may be a resin polycondensed by melt polymerization from terephthalic acid or an alkyl terephthalic acid ester and a glycol component having 2 to 10 carbon atoms.

Examples of the polyester resin include polyethylene terephthalate resin, polytrimethylene terephthalate resin, polybutylene terephthalate resin, polyhexamethylene terephthalate resin, polycyclohexane dimethylene terephthalate resin, bibenzene-modified polyethylene terephthalate. (bibenzene-modified polyethylene terephthalate), bibenzene-modified polybutylene terephthalate, bibenzene-modified polyethylene naphthalate, polyester resins obtained by modifying these resins to be amorphous, and the like, and these alone or both It can be used by mixing the above. Examples of the mixed use include a mixture of the polyethylene terephthalate resin and the polybutylene terephthalate resin.

(B) carbon black

In the present invention, the carbon black may have an average particle diameter of 10 to 200 nm, preferably 10 to 100 nm, more preferably 10 to 20 nm. When the average particle diameter of the carbon black exceeds 200 nm, sufficient blackness cannot be imparted to the prepared polyester yarn, and it is difficult to uniformly disperse due to self-agglomeration when manufacturing the master chip due to the excessive specific surface area, and for this reason, the process Since there is a high possibility of causing a phase problem, it is very important to control the average particle diameter of carbon black within the above range.

In addition, the specific surface area of the carbon black may be 400 m2/g or less, preferably 100 to 400 m2/g, more preferably 150 to 350 m2/g, more preferably 200 to 300 m2/g, , it is preferable to have a specific surface area within the above range in order to maintain sufficient color tone of the polyester yarn and prevent agglomeration of carbon black.

The surface pH of carbon black is slightly alkaline and some is acidic in neutral, however, polyester resins tend to be hydrolyzed by alkali. Therefore, neutral to acidic carbon black is suitable, and it is preferable that the surface pH is 3-7.

A mixture of polyester resin, carbon black powder, and aliphatic carbodiimide compound exhibits different pH values as the number of -COOH and -OH groups appearing on the surface of the mixture varies depending on the type of carbon black. The higher the pH of the surface of the carbon black, the poorer the dispersibility of the carbon black. When the pH value is 7 or less in an acidic region, more preferably, when the pH value is 3 to 4, the dispersion stability is the most excellent. When it is lowered below the above range, as the number of -OH groups or -COOH groups on the carbon black surface increases, the number of sites capable of bonding with the aliphatic carbodiimide increases, and dispersion stability is improved.

Aliphatic Carbodiimide Compounds

As the aliphatic carbodiimide used as the hydrolysis resistance additive in the present invention, a compound represented by the following Chemical Formula 1 may be used.

[Formula 1]

R ₁ -N=C=NR ₂

In the above formula, R ₁ and R ₂ are each independently an aromatic group having 5 to 30 carbon atoms, an alicyclic group having 5 to 20 carbon atoms, or a bulky alkyl group having 5 to 30 carbon atoms.

Specifically, the aliphatic carbodiimide compound may be a compound represented by Formula 2 below.

[Formula 2]

In the above formula, R ₃ , R ₄ , R ₅ , and R ₆ are each independently a hydrogen atom, a linear or branched alkyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 8 carbon atoms.

Preferred radicals R ₃ to R ₆ are each independently ethyl, propyl, isopropyl, sec-butyl, tert-butyl, cyclohexyl, dodecyl, phenyl, tolyl, benzyl or naphthyl. In general, carbodiimides are available as commercial products.

Specific examples of the aliphatic carbodiimide compound include N,N'-di-o-tolylcarbodiimide, N,N'-diethylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N '-di-2,6-diketylphenylcarbodiimide, N-tolyl-N'cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N' -di-2,6-di-tertiary-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'- Di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, N,N'-di-p-tolylcar Bodyimide, p-phenylene-bis-di-o-tolylcarbodiimide, p-phenylene-bisdicyclohexylcarbodiimide, hexamethylene-bisdicyclohexylcarbodiimide, ethylene-bisdiphenylcarbodiimide Meide, benzene-2,4-diisocyanato-1,3,5-tris(1-methylethyl) homopolymer, 2,4-diisocyanato-1,3,5-tris(1-methylethyl) and a copolymer of 2,6-diisopropyl diisocyanate, and the like, but is not limited thereto.

The hydrolysis resistance additive may be included in an amount of 1 wt% to 4 wt%, specifically 2 to about 3 wt%, based on 100 wt% of a mixture of the polyester resin and carbon black. If the content of the aliphatic carbodiimide compound is less than 1% by weight, the effect of improving hydrolysis resistance may be insufficient, and if the content of the aliphatic carbodiimide compound exceeds 4% by weight, thermal decomposition is caused, thereby increasing the oligomer content to increase physical properties , and the screw load can also be reduced.

Other components may be further added to the carbon black masterbatch composition of the present invention as needed. Examples of such additives include fillers, reinforcing agents, weatherability modifiers, foaming agents, lubricants, fluidity modifiers, impact modifiers, dyes, pigments, dispersants, and the like.

For example, as a filler or a reinforcing agent, either organic or inorganic may be used, but in general, it is preferable to use an inorganic material such as glass fiber, talc, potassium titanate, calcium carbonate, and silica.

The polyester-based carbon black masterbatch composition of the present invention may be prepared by melt-kneading. Melt-kneading, for example, blends the polyester resin with carbon black and, if necessary, an aliphatic carbodiimide compound or other additives as described above, and mixes uniformly with a Henschel mixer, a ribbon blender, a V-type blender, etc. Then, it can be carried out by kneading in a molten state by heating with a single-screw or multi-screw kneading extruder, roll, Banbari mixer, Labo PlastoMill (Brabender), or the like. On the other hand, instead of mixing and kneading all the components at once, some components may be mixed beforehand, or it may supply in the middle of kneading|mixing without mixing beforehand. The kneading temperature and kneading time vary depending on the desired polyester-based carbon black masterbatch composition or the type of kneader, etc. In general, the kneading temperature is 200 to 350°C, preferably 220 to 320°C, and the kneading time is 20 Minutes or less are preferred. When it exceeds 350 degreeC or 20 minutes, the thermal deterioration of a polyester resin becomes a problem, and the fall of the physical property of a yarn or a molded article, or appearance may generate|occur|produce.

The polyester-based carbon black masterbatch composition pellets thus obtained can be molded using molding methods generally used for thermoplastic resins, for example, injection molding, extrusion, blow molding, thermoforming, press molding, etc. . Among them, the injection molding method is preferable from the viewpoint of productivity and product performance.

It is possible to prepare a polyester original yarn manufactured by mixing the carbon black masterbatch of the present invention with an existing polyester chip in a predetermined ratio through melt spinning and spinning processes. The polyester yarn manufacturing method can be prepared by preparing a polyester carbon black masterbatch according to the method of the present invention, inserting the carbon black masterbatch and a general polyester chip together, melt spinning, and stretching. In the present invention, the spinning method is not particularly limited, and dry spinning, wet spinning, and melt spinning other than chemical spinning may be used, and in particular, it is effective to use the dry spinning method.

The present invention may be better illustrated by the following examples, which are for illustrative purposes only and are not intended to limit the scope of protection defined by the appended claims.

Example

Example 1

74.92 kg of polyethylene terephthalate chips with an intrinsic viscosity of 1.0 g/dL, an average particle size of 10 nm, a specific surface area of 550 m/g, and 25 kg of carbon black (Degussa) having a surface pH of 4 and an aliphatic car of Formula 1 as a hydrolysis inhibitor 0.75 kg of bodyimide compound was mix|blended, and it mixed uniformly with a tumbler mixer. After this was extruded at 250° C. in a twin-screw extruder having L/D=29 and a diameter of 45 mm, the extrudate was prepared in the form of pellets. Then, the oligomer content (%) and screw load were measured, and the results are shown in Table 2 below.

Comparative Example 1

After preparing pellets in the same manner as in Example 1 except that no hydrolysis inhibitor was added, physical properties of the prepared pellets were measured, and the results are shown in Table 2 below.

Comparative Example 2

After preparing pellets in the same manner as in Example 1 except that the content of the hydrolysis inhibitor was changed as shown in Table 2 below, the physical properties of the prepared pellets were measured and the results are shown in Table 2 below. indicated.

Test Example: Measurement of physical properties

The physical properties of the pellets obtained in Examples and Comparative Examples were measured by the following method.

(1) oligomer content

_{After dissolving 5 ml of HFIP/CH 2} Cl ₂ = 1/3 (v/v) of a sample of about 0.1 g of PET chip, reprecipitation with 10 mL of acetonitrile was used to analyze the oligomer content using HPLC. At this time, HPLC analysis conditions were set as shown in Table 1 below.

device used Waters UPLC Column X-bridge C18 5㎛ (4.6×250mm) Eluent : A/B=90/10→A/B=0/100→A/B=90/10
A: 0.3% H ₃ PO ₄ B: CH ₃ CN flow rate 1.0 ml/min (5.0μL Inj, Run time 40 min ) Detection UV Detector at 242 nm

(2) screw load

When the carbon black masterbatch is manufactured, when the screw is rotated at the same rpm, the higher the viscosity, the higher the load (A) value.

(3) Strength, Elongation, and Toughness

The yarn strength/elongation and toughness values are the results measured by manufacturing the original yarn at a ratio of 95% PET chip and 5% carbon black M/B.

division Comparative Example 1 Example 1 Example 2 Comparative Example 3 PET chip input (kg) 75 74.25 72.75 71.25 Carbon black input (kg) 25 25 25 25 Aliphatic Carbodiimide
Compound dosage (kg) 0 0.75 2.25 3.75 Compared to PET chips
Hydrolysis inhibitor concentration (%) 0 One 3 5 Oligomer content (%) 1.1 1.1 1.1 1.4 screw load (A) 130 140 142 138 Yarn strength (g/d) 4.20 4.27 4.32 4.24 Yarn Elongation (%) 36.4 37.2 37.5 37.0 toughness 25.3 26.0 26.5 25.8

As can be seen from the results in Table 2, when the carbon black masterbatch was prepared, in the case of Examples 1 and 2, the screw load value was as high as 140 to 142, and it was confirmed that hydrolysis was most prevented. In contrast, in the case of Comparative Example 2, in which the content of the aliphatic carbodiimide compound was 5 wt % compared to the PET chip, thermal decomposition was caused due to an excessively large content, which resulted in an increase in the oligomer content to decrease the physical properties, and the screw load was also was found to be low.

In the above, the present invention has been described in detail only with respect to the described embodiments, but it is apparent to those skilled in the art that various changes and modifications are possible within the scope of the technical spirit of the present invention, and it is natural that such variations and modifications belong to the appended claims. .

Claims (10)

A polyester-based carbon black masterbatch composition comprising a polyester resin, carbon black having a surface pH of 3 to 7, and an aliphatic carbodiimide represented by the following formula (1).
[Formula 1]
R ₁ -N=C=NR ₂
In the above formula, R ₁ and R ₂ are each independently an aromatic group having 5 to 30 carbon atoms, an alicyclic group having 5 to 20 carbon atoms, or a bulky alkyl group having 5 to 30 carbon atoms.
The polyester-based carbon black masterbatch composition according to claim 1, wherein the aliphatic carbodiimide compound is a compound represented by the following Chemical Formula 2:
[Formula 2]

In the above formula, R3, R4, R5, and R6 are each independently a hydrogen atom, a linear or branched alkyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 8 carbon atoms. The polyester-based carbon black masterbatch composition according to claim 1, wherein the carbon black has an average particle size of 10 to 200 nm and a specific surface area of 160 to 340 m 2 /g.
The polyester-based carbon black masterbatch composition according to claim 1, wherein the masterbatch composition has a water content of 4 or more and an intrinsic viscosity of 0.3 to 0.6.
According to claim 1, wherein the polyester resin, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polytrimethylene terephthalate, bibenzene-modified polyethylene terephthalate (bibenzene-modified polyethylene terephthalate), bibenzene - A polyester-based carbon black masterbatch composition, characterized in that it is selected from the group consisting of modified polybutylene terephthalate, bibenzene-modified polyethylene naphthalate, or a mixture thereof.
A method for producing a polyester-based carbon black masterbatch, comprising mixing a polyester resin, carbon black having a surface pH of 3 to 8, and an aliphatic carbodiimide represented by the following formula (1).
[Formula 1]
R ₁ -N=C=NR ₂
In the above formula, R ₁ and R ₂ are each independently an aromatic group having 5 to 30 carbon atoms, an alicyclic group having 5 to 20 carbon atoms, or a bulky alkyl group having 5 to 30 carbon atoms.
The method according to claim 6, wherein the aliphatic carbodiimide compound is a compound represented by the following formula (2):
[Formula 2]

In the above formula, R ₃ , R ₄ , R ₅ , and R ₆ are each independently a hydrogen atom, a linear or branched alkyl group having 2 to 20 carbon atoms, or a cycloalkyl group having 3 to 8 carbon atoms.
The method according to claim 6, wherein the carbon black has an average particle size of 10 to 30 nm and a specific surface area of 160 to 340 m 2 /g.
The method of claim 6, wherein the masterbatch composition has a water content of 4 or more and an intrinsic viscosity of 0.3 to 0.6.
The method of claim 6, wherein the polyester-based polyester resin is polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polytrimethylene terephthalate, bibenzene-modified polyethylene terephthalate (bibenzene-modified polyethylene terephthalate) , bibenzene-modified polybutylene terephthalate, bibenzene-modified polyethylene naphthalate, or a mixture thereof.