DESC:FIELD
The present disclosure relates to a delustering composition for polymers and its process of preparation.

BACKGROUND
Freshly prepared polymer fibers commonly possess a distinct shine that is undesirable in view of their use in diverse applications. Addition of delustering agents to render the polymers dull or opaque is a common practice known in the art.

Use of various substances as delustering agents has been explored till date.US 20070249773 and US 7476704 report use of Titanium dioxide (TiO2) and other particulate inorganic substances for the preparation of dull synthetic fibers. The fibers that result from using the substances of the present disclosure, however, become patchy, which may prejudice aesthetics of the synthetic fibers. Further, TiO2 is an expensive chemical which makes the process of delustering fibers expensive. A need is, therefore, felt to find alternative delustering agents and/ or compositions that render the polymer delustering process cost and time efficient and produces uniformly delustered polymers.

OBJECTS
Some of the objects of the present disclosure, of which at least one embodiment is adapted to provide, are described herein below:
It is an object of the present disclosure to provide a delustering composition for polymers.
It is another object of the present disclosure to provide a delustering composition for polymers which is economical.
It is still another object of the present disclosure to provide a delustering composition for polymers which achieves uniform delustering of polymers.
It is yet another object of the present disclosure to provide a process for the preparation of the delustering composition for polymers.
It is still another object of the present disclosure to provide a process for delustering fibers using the delustering composition for polymers.
It is yet another object of the present disclosure to provide polymer fibers delustered using the composition of the present disclosure.
It is still another object of the present disclosure to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present disclosure.

SUMMARY
The present disclosure provides a polymer delustering composition comprising at least one inorganic compound in an amount ranging from 2 to 50 wt%, at least one dispersing agent 0.1 to 5 wt%, at least one carrier medium in an amount ranging from 45 to 95 wt% and optionally, titanium dioxide in an amount ranging from 0 to 25 wt%. The present disclosure also provides a process for the preparation of the polymer delustering composition that includes milling the ingredients individually or together. Further, the present disclosure also provides a process for delustering polymers comprising incorporating the afore-stated composition into polymeric material before, during or after esterification.

DETAILED DESCRIPTION
Freshly prepared polymers are often associated with a typical shine, which mars its aesthetics. Various delustering agents have been used to tackle this problem, however, the resulting delustered polymers have been found to be non-uniformly delustered.
In accordance with one aspect of the present disclosure, there is provided a delustering composition for polymers that includes at least one inorganic compound, at least one dispersing agent, at least one carrier medium and optionally, titanium dioxide. Typically, the present composition is used for delustering at least one polymer selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polytrimethylene terephthalate.
The inorganic compound(s) of the present disclosure have particle size ranging from 0.2 to 0.8 microns and are present in an amount ranging from 2 to 50% of the total weight of the composition. The particle size is maintained in a specific range to avoid problems associated with pack pressure raise and frequent breaks during spinning. The inorganic compound(s) of the present disclosure are used as opacifiers for delustering polymers and are used to partially and even completely replace use of titanium dioxide. The inorganic compound(s) used in the present composition include at least one compound selected from the group consisting of calcium carbonate, barium carbonate, boric acid, boron trifluoride, boron trichloride, zinc sulfate, silica, barium sulfate, kaolin and lithopone (ZnS: BaSO4:: 30: 70).
The dispersing agent(s) of the present disclosure are in close association with the inorganic particles and are used for effectively dispersing the inorganic compounds throughout the body of the polymers to achieve uniform delustering. The dispersing agent(s) are present in an amount ranging from 0.1 to 5 % of the total weight of the composition and are at least one selected from the group consisting of polyacrylic acid salt, sulfonate copolymer sodium salt, carboxylate copolymer sodium salt and sodium hexametaphosphate. In one embodiment, the copolymer is a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid in 70: 30 ratio.
Titanium dioxide may optionally be present in the composition of the present disclosure having particle size ranging from 0.1 to 0.5 microns. The amount of titanium dioxide, typically, ranges from 0 to 25% of the total weight of the composition.
The carrier medium used in the present disclosure is at least one selected from the group consisting of monoethylene glycol and water and is present in an amount ranging from 45 to 95 % of the total weight of the composition. The carrier medium is used to form slurry along with the afore-stated ingredients during the process of preparation of the composition of the present disclosure.
In accordance with another aspect, the present disclosure provides a process for the preparation of the polymer delustering composition. The process includes milling the ingredients independently or together.
In one embodiment, at least one inorganic compound and at least one dispersing agent, in the afore-stated quantities, are milled in the presence of at least one carrier medium to obtain a first slurry. Optionally, titanium dioxide, in the afore-stated quantity, is milled independently in the presence of the carrier medium to obtain a second slurry. Next, the first and the second slurry are blended together to obtain the polymer delustering composition of the present disclosure. Typically, the carrier medium used in the two afore-stated steps is the same or may be different.
In another embodiment, at least one inorganic compound, at least one dispersing agent and optionally, titanium dioxide, in the afore-stated quantities, are milled together in the presence of at least one carrier medium, to obtain the polymer delustering composition.
As the present composition comprises CaCO3 and other inorganic compounds which are cheaper than TiO2, the present composition is more economical than the conventional TiO2 based/ predominant delustering compositions.
In accordance with yet another aspect of the present disclosure, a process for delustering polymers using the present composition is provided. The process includes incorporating the composition into the polymeric material before, during or after the step of esterification.
The present disclosure will now be discussed in the light of the following non-limiting embodiments:
Example 1: Process for the preparation of the composition of the present disclosure
CaCO3 and TiO2 were milled independently in monoethylene glycol using NETZSCH mill for 4 hours to obtain first and second slurry respectively. To improve the slurry stability, 2 wt% polycarboxylate sodium salt of a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid (70:30 ratio) based on the total weight of the solids, was added as a dispersing agent during the milling of CaCO3. The particle size after milling both slurries was found to be less than 0.5 microns. The first and second slurries were blended together to obtain the delustering composition of the present disclosure. The delustering composition contained 20 wt% solids and comprised TiO2 and CaCO3 in the ratio 75:25.
Example 2: Process for delustering using the composition of the present disclosure
2A] Delustering composition containing titanium dioxide only (Control)
Purified terephthalic acid was esterified with monoethylene glycol (MEG) in 1:2 ratio at 260 °C. The oligomer obtained further underwent transesterification at 290 °C to obtain amorphous polymer having intrinsic viscosity (IV) of up to 0.6 dl/g. About 290 ppm of antimony was added as a catalyst along with 0.26 wt% of TiO2 after the esterification reaction. No dispersing agent was used. The polymer extruded out of the reactor in a strand form was cut into pellets and named as CONTROL resin. The pellets were crystallized in a crystallizer at 150 °C and dried at 160 °C for 5 hours. The dried chips were extruded from a 36 hole spinneret at 280-285 °C, quenched using cold air at 18 °C and taken up for spinning at a speed of 2900 m/min.
2B] Delustering composition containing titanium dioxide and calcium carbonate (75: 25)
Purified terephthalic acid was esterified with MEG in 1:2 ratio at 260 °C. The oligomer obtained further underwent transesterification at 290 °C to obtain amorphous polymer having IV up to 0.6 dl/g. About 290 ppm of antimony was added as a catalyst along with 0.26 wt% (based on the total weight of solids) of the delustering composition of Example 1 after the esterification reaction. The polymer extruded out of the reactor in a strand form was cut into pellets and crystallized in a crystallizer at 150 °C and dried at 160 °C for 5 hours. The dried chips were used for spinning as mentioned in Example 2A.
2C] Delustering composition containing titanium dioxide and calcium carbonate (50: 50)
The procedure carried out in Example 2A was repeated except that the 0.26% delustering composition (based on the total weight of solids) comprised TiO2 and CaCO3 in the ratio 50:50.
2D] Delustering composition containing titanium dioxide and lithopone(50: 50)
The procedure carried out in Example 2A was repeated except that the 0.26% delustering composition (based on the total weight of solids) comprised TiO2 and lithopone in the ratio 50:50.
The delustered fibers obtained in Examples 2A to 2D were studied for various physical and optical properties and the results obtained are presented herein below.
Table 1: Polymerization composition and properties
Polymerization Units Ex-1 Ex-2 Ex-3 Ex-4
Mole ratio 1 : 2 1 : 2 1 : 2 1 : 2
Sb2O3 290 290 290 290
NaOH ppm NaOH 25 25 25 25
TiO2 % 0.26 0.195 0.13 0.13
Additive (inorganic compound) % Nil 0.065 0.13 0.13
IV dl/g 0.626 0.629 0.614 0.614
L* Hunter 83.8 81.8 77.56 76.59
a* Hunter -1.16 -1.36 -1.86 -1.51
b* Hunter 3.91 3.98 4.19 5.48
COOH meq/kg 24 24 25 28
Table 2: Physical properties of the resultant yarns
Properties Units Ex-1 Ex-2 Ex-3 Ex-4
Cross Section Round Round Round Round
Type Partially oriented yarn (POY) POY POY POY
Denier/fil. NA 130/36 130/36 130/36 130/36
Winder Speed mpm 2900 2900 2900 2900
Actual Denier NA 130 129.5 128.7 130.3
Draw Tension g 32.5 36.7 36.7 29.2
Tenacity gpd 2.6 2.8 2.61 2.2
Elongation % 147 145 141.8 153

Table 3: Optical properties of POY
Parameter Ex-1 Ex-2 Ex-3 Ex-4
Color L* Hunter 93.9 93.8 93.6 93.6
a* -0.35 -0.39 -0.35 -0.44
b* 1.07 1.34 1.28 1.27
Gloss

20° 9.3 8.5 9.4 8.53
60° 32.5 31.3 37.9 33
85° 41.4 29.6 36.3 38.12

The coefficient of friction between yarn-metal; yarn-ceramic and yarn-yarn were measured. It was observed that friction in Y/M in Ex-2 is slightly reduced than control which may perform better in downstream process.

Coefficient of Friction:
Table 4. Coefficient of Friction
Friction Yarn speed Ex-1 Ex-2 Ex-3
Yarn to Metal 100 m/min 0.768 0.736 0.7393
Yarn to ceramic 100 m/min 0.437 0.425 0.4215
Yarn to Yarn 50 m/min 0.613 0.612 0.5431

Texturized yarn:
Texturizing was carried to increase bulkiness of the yarn. Overall texturizing performance was found to be satisfactory. Good bulk was observed. Color values of the polyester texturized yarn (PTY yarn) were found to be comparable with control. Gloss value for texturized sample was comparable to control. The results revealed that the delustering composition achieved a gloss similar to that of the control.
Table 5. Optical properties of the texturized yarn
Ex-1 Ex-2
PTY color L* Hunter 93.61 94.03
a* -0.12 -0.13
b* 0.53 0.65
Gloss

20 °
2.2 2.2
60 ° 8.3 8.9
85 ° 3.7 3.2

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description.
Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE
- The present disclosure provides for cost effective replacement of titanium dioxide which is an expensive raw material used for polymer delustering; thereby making the overall delustering process economical.
- The delustering composition of the present disclosure yields uniformly delustered polymers having desirable properties such as color, tenacity, gloss, dyeability, spinning and texture performance.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results.
The numerical values given for various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the invention and the claims unless there is a statement in the specification to the contrary.

While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications in the process or compound or formulation or combination of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention. ,CLAIMS:1. A delustering composition for polymers comprising:
i. at least one inorganic compound selected from the group consisting of calcium carbonate, barium carbonate, boric acid, boron trifluoride, boron trichloride, zinc sulfate, silica, barium sulfate, kaolin and lithopone in an amount ranging from 2 to 50 % of the total weight of the composition;
ii. at least one dispersing agent in an amount ranging from 0.1 to 5 % of the total weight of the composition;
iii. at least one carrier medium in an amount ranging from 45 to 95 % of the total weight of the composition; and
iv. titanium dioxide in an amount ranging from 0 to 25 % of the total weight of the composition.
2. The delustering composition for polymers as claimed in claim 1, wherein said inorganic compound has particle size ranging from 0.2 to 0.8 microns.
3. The delustering composition for polymers as claimed in claim 1, wherein said dispersing agent is at least one selected from the group consisting of polyacrylic acid salt, sulfonate copolymer sodium salt, carboxylate copolymer sodium salt and sodium hexametaphosphate.
4. The delustering composition for polymers as claimed in claim 3, wherein said copolymer is a copolymer of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid.
5. The delustering composition for polymers as claimed in claim 1, wherein said titanium dioxide has particle size ranging from 0.1 to 0.5 microns.
6. The delustering composition for polymers as claimed in claim 1, wherein said carrier medium is at least one selected from the group consisting of monoethylene glyol and water.
7. The delustering composition for polymers as claimed in claim 1, wherein said polymer is at least one polyester selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and polytrimethylene terephalate.
8. A process for the preparation of the delustering composition for polymers as claimed in claim 1; said process comprising the following steps:
i. milling at least one inorganic compound in an amount ranging from 2 to 50 % of the total weight of the composition and at least one dispersing agent in an amount ranging from 0.1 to 5 % of the total weight of the composition, in the presence of at least one carrier medium to obtain a first slurry;
ii. optionally, milling titanium dioxide in an amount ranging from 0 to 25 % of the total weight of the composition, in the presence of at least one carrier medium to obtain a second slurry; and
iii. blending said first slurry and said second slurry to obtain the delustering composition for polymers.
9. The process as claimed in claim 8, wherein said carrier medium is present in an amount ranging from 45 to 95 % of the total weight of the composition.
10. The process as claimed in claim 8, wherein said carrier medium used in steps (i) and (ii) is the same.
11. The process as claimed in claim 8, wherein said carrier medium used in steps (i) and (ii) is different.
12. A process for the preparation of the delustering composition for polymers as claimed in claim 1, comprising milling at least one inorganic compound in an amount ranging from 2 to 50 % of the total weight of the composition, at least one dispersing agent in an amount ranging from 0.1 to 5 % of the total weight of the composition and optionally, titanium dioxide in an amount ranging from 0 to 25 % of the total weight of the composition, in the presence of at least one carrier medium in an amount ranging from 45 to 95 % of the total weight of the composition, to obtain the delustering composition for polymers.
13. A process for delustering polymers comprising incorporating the composition as claimed in claim 1, into polymeric material before, during or after esterification reaction.
14. Delustered polymeric fibers prepared by the processes as claimed in claim 8 or 10, comprising particles of said delustering composition in an amount ranging from 0.03 to 3 wt%.