WO2019204227A1 - Polyamide dispersions - Google Patents

Abstract

A process of producing a polyamide dispersion includes heating a polyamide to above its melting point; adding a surfactant to form a mixture; under shearing conditions, adding water solution having a basic pH to the mixture to form a sheared mixture; and cooling the sheared mixture to provide the polyamide dispersion; wherein the process is conducted in the absence of an organic solvent, and the sheared mixture comprises particles of a polyamide having a volume mean particle size of less than 1 micron.

Description

POLYAMIDE DISPERSIONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.

62/658,106, filed April 16, 2018, the contents of which are incorporated herein by reference in its entirety.

FIELD

[0002] The present technology is generally related to polymer dispersions. More particularly, it is related to polyamide dispersions in water.

BACKGROUND

[0003] Polyamide resins are a well-known class of resins, manufactured by a

condensation reaction between acid- and amine-functionalized reactants. Selection of chain length and functionality determines the final properties of the polyamide resin. Polymerized fatty acids may enhance resin properties such as flexibility and film formation. The polyamide resins find use as binders for printing inks, water resistant coatings, and hot melt adhesives such as road markings. Product applications typically do use solvents such as alcohols to dissolve the polyamide resin into the final formulation. New formulations, moving away from solvents and / or aiming to reduce VOC, are looking for quality polyamide dispersions.

SUMMARY

[0004] In one aspect, a method is provided for the preparation of a stable polyamide dispersion of fine particle size, without the use of solvents nor aromatic surfactants. The compositions and processes to manufacture such products are also described.

DETAILED DESCRIPTION

[0005] Various embodiments are described hereinafter. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment(s).

[0006] As used herein,“about” will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used,“about” will mean up to plus or minus 10% of the particular term.

[0007] The use of the terms“a” and“an” and“the” and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language ( e.g .,“such as”) provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0008] In one aspect, a method is provided for the preparation of stable polyamide dispersions of fine particle size without the use of organic solvents or aromatic surfactants. In the present methods, a polyamide resin is heated above its softening point and an aliphatic surfactant is added. The molten blend is subjected to shear forces in the presence of water, using an inversion process, using a batch process or continuous process, to produce the polyamide dispersion. The product is subsequently cooled to room temperature. The final dispersion has a volume average particle size of 1 micron or less, preferably 0.5 micron or less. The final dispersion exhibits high solids, typically 45% and higher, and long product shelf life, typically 3 months or longer. As used herein, the“inversion process” is a process in which a water in oil emulsion is converted to an oil in water emulsion. In some embodiments, the inversion process is a batch inversion emulsification.

[0009] In one embodiment, the aliphatic surfactant is an anionic surfactant. For example, the aliphatic surfactant may be an anionic, non-aromatic surfactant. In other embodiments, the aliphatic surfactant is a fatty alcohol ether phosphate surfactant.

[0010] In another embodiment, the polyamide is blended with a resin, prior to

emulsification. For example, the resin may include a rosin resin, a hydrocarbon resin, a polyterpene resin, or a terpene phenol resin.

[0011] In a further embodiment, the polyamide may exhibit one or more of the following properties: a melting point of 90°C to l25°C; an acid value of less than or equal to 10 mg

KOH/gram; an amine value of less than or equal to 10 mg KOH/gram; and/or a melt viscosity at 160° C of 150 to 55,000 mPa-s.

[0012] The dispersion may have a volume average particle size of from greater than 0 to about 1 micron. This may include from greater than 0 to about 0.5 micron, from greater than 0 to about 0.25 micron, from about 0.05 to about 1 micron, from about 0.05 to about 0.5 micron, from about 0.1 to about 1 micron, from about 0.1 to about 0.5 micron, from about 0.2 to about 1 micron, or from about 0.2 to about 0.5 micron.

[0013] The final dispersion may exhibit a solids percentage of from about 45% to about

99%. This may include from about 45% to about 90%, from about 45% to about 75%, from about 50% to about 95%, from about 50% to about 90%, from about 50% to about 75%, from about 60% to about 95%, from about 60% to about 90%, from about 60% to about 80%, from about 75% to about 99%, from about 75% to about 95%, or from about 45% to about 90%. The shelf life may be about 3 months to 5 years, from about 3 months to 2.5 years, from about 3 months to about 1 year, from about 6 months to about 5 years, from about 6 months to about 2.5 years, from about 6 months to about 1 year, from about 1 year to about 5 years, or from about 1 year to about 2.5 years. As used herein, shelf stable means that the viscosity of the final blend does not change by more than 90% over the time period, does not change by more than 80% over the time period, does not change by more than 70% over the time period, does not change by more than 60% over the time period, does not change by more than 50% over the time period, does not change by more than 40% over the time period, does not change by more than 30% over the time period, does not change by more than 20% over the time period, does not change by more than 10% over the time period, does not change by more than 5% over the time period, or does not change by more than 2% over the time period.

[0014] As noted above the dispersion may have a melt viscosity at 160° C of about 150 to about 55,000 mPa-s. This may include from about 150 to about 55,000 mPa-s, from about 250 to about 40,000 mPa-s, from about 500 to about 25,000 mPa-s, from about 500 to about 10,000 mPa-s, from about 150 to about 1,500 mPa-s, from about 150 to about 10,000 mPa-s, or from about 150 to about 1,500 mPa-s.

[0015] In other embodiments, the polyamide resin may have a softening point, as measured by a ring and ball, of about 75°C to about l50°C. This may include a softening point from about 95°C to about l20°C, from about 95°C to about 1 l0°C, from about l00°C to about 105 °C.

[0016] In another aspect, a polyamide dispersion is provided that is produced according to any of the processes described herein.

[0017] The present invention, thus generally described, will be understood more readily by reference to the following examples, which are provided by way of illustration and are not intended to be limiting of the present invention.

EXAMPLES

[0018] Example 1. A polyamide resin (1000 grams), having a ring and ball softening point of 102 °C, is heated at 170 °C where it becomes molten. The molten resin is then cooled to 145 °C, and, with stirring, a fatty alcohol ether phosphate surfactant (80 g; Servoxyl VPDZ 9/100) is added, followed by aqueous ammonia (175 g or 5.7 wt% in water). Under stirring, water (50 grams at 90 °C) is added at a rate of 100 grams per minute. The mixing is continued for 2 minutes, and subsequently the stirring is slowed and water (600 grams at 90 °C; and 500 grams of water) is added at a rate of 400 grams per minute. After the water addition, the dispersion is cooled to room temperature. The final polyamide resin dispersion has a solids level of 47 wt%, a room temperature viscosity of 740 mPas, and a volume mean particle size of 0.19 microns.

[0019] Example 2. The same formulation is used as in Example 1, but a twin screw extruder for the emulsification. The polyamide resin is heated until molten in the first section of the extruder, using kneading blocks. The aqueous phase, containing the surfactant and ammonia in water, is added under homogeneous blending in the kneading blocks at 85 wt% solids. The second phase water is added in the last part of the extruder followed by product cooling. The final polyamide resin dispersion has a solids level of 45 wt%, a room temperature viscosity of 1200 mPas, and a volume mean particle size of 0.31 microns.

[0020] Example 3. A polyamide resin (500 grams), having a ring and ball softening point of 102° C, is heated at 170° C where it becomes molten. To the melt is added a rosin glycerol ester (500 grams) and the temperature is maintained at 170° C allowing melting and blending while stirring. The molten blend is then cooled to 145° C, and, with stirring, a fatty alcohol ether phosphate surfactant (80 grams; Servoxyl VPDZ 9/100) is added, followed by aqueous ammonia (175 grams or 5,7 wt% in water). With stirring, water (50 grams at 90 °C) is added at a rate of 100 grams per minute. The mixing is continued for 2 minutes, and

subsequently the stirring is slowed and water (600 grams at 90 °C; and 500 grams at 20 °C) is added at a rate of 400 grams per minute. After the water addition, the dispersion is cooled to room temperature. The final polyamide and rosin glycerol ester blend dispersion has a solids level of 46 wt%, a room temperature viscosity of 240 mPa· s, and a volume mean particle size of 0.14 microns.

[0021] Example 4. A polyamide resin (500 grams), having a ring and ball softening point of 102° C, is heated at 170° C where it becomes molten. To the melt a hydrocarbon resin (500 grams) is added and temperature is maintained at 170° C allowing melting and blending while stirring. The molten blend is then cooled to 145° C, and, with stirring, a fatty alcohol ether phosphate surfactant (80 grams; Servoxyl VPDZ 9/100) is added, followed by aqueous ammonia (175 grams or 5.7 wt% in water). Under stirring, water (50 grams at 90° C) is added at a rate of 100 grams per minute. The mixing is continued for 2 minutes, and subsequently the stirring is slowed and water (600 grams at 90° C; and 500 grams at 20° C) is added at a rate of 400 grams per minute. After the water addition, the dispersion is cooled to room temperature. The final polyamide and hydrocarbon resin blend dispersion has a solids level of 46 wt%, a room temperature viscosity of 150 mPa-s, and a volume mean particle size of 0.25 mM.

[0022] Example 5. A polyamide resin (1000 grams), having a ring and ball softening point of 102° C, is heated at 170° C where it becomes molten. Temperature is maintained at 170° C allowing melting while stirring. The melt is then cooled to 130° C, and, with stirring, a fatty alcohol ether sulfate surfactant (150 grams; Sermul EA266) is added. Subsequently the stirring is slowed and water (600 grams at 90° C; and 500 grams at 20° C) is added at a rate of 400 grams per minute. After the water addition, the dispersion is cooled to room temperature. The final polyamide dispersion has a solids level of 46 wt%, a room temperature viscosity of 700 mPa· s, and a volume mean particle size of 0.30 microns.

[0023] Paragraph A. A method of producing a polyamide resin dispersion without organic solvents, with fine particle size, of volume mean particle size less than 1 micron.

[0024] Paragraph B. A method to produce polyamide resin dispersions according to

Paragraph A, using anionic surfactants and inversion process emulsification.

[0025] Paragraph C. A method to produce polyamide resin dispersions according to any one of Paragraphs A and B, using anionic non aromatic surfactants and inversion process emulsification.

[0026] Paragraph D. A method to produce polyamide resin dispersions according to any one of Paragraphs A-C, using anionic non aromatic surfactants and batch inversion process emulsification. [0027] Paragraph E. A method to produce polyamide resin dispersions according to any one of Paragraphs A-D, using anionic non aromatic surfactants and continuous inversion process emulsification.

[0028] Paragraph F. A method to produce polyamide resin dispersions according to any one of Paragraphs A-E, using fatty alcohol ether phosphate surfactants and batch inversion process emulsification.

[0029] Paragraph G. A method to produce polyamide resin dispersions according to any one of Paragraphs A-F, producing a volume average particle size of 0,5 micron or less, using fatty alcohol ether phosphate surfactants and continuous inversion process emulsification.

[0030] Paragraph H. A method to produce polyamide resin dispersions according to any one of Paragraphs A-G, wherein the polyamide is blended with a resin, prior to emulsification.

[0031] Paragraph I. A method to produce polyamide resin dispersions according to any one of Paragraphs A-H, wherein the resin comprises a rosin resin, a hydrocarbon resin, a polyterpene resin, or a terpene phenol resin.

[0032] Paragraph J. A method to produce polyamide resin dispersions according to any one of Paragraphs A-I, where the surfactant comprises a fatty alcohol ether sulfate surfactant.

[0033] Paragraph K. A method to produce polyamide resin dispersions according to any one of Paragraphs A-J, where the polyamide exhibits one or more of the following properties: a melting point of 90°C to l25°C; an acid value of less than or equal to 10 mg KOH/gram; an amine value of less than or equal to 10 mg KOH/gram; and a melt viscosity at 160° C of 150 to 55,000 mPa s.

[0034] Paragraph L. A polyamide dispersion produced according to Paragraph A, B, C,

D, E, F, G, H, I, J, or K.

[0035] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects as defined in the following claims.

[0036] The embodiments, illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms“comprising,”“including,”“containing,” etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase“consisting essentially of’ will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase “consisting of’ excludes any element not specified.

[0037] The present disclosure is not to be limited in terms of the particular embodiments described in this application. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and compositions within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds compositions or biological systems, which can of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0038] In addition, where features or aspects of the disclosure are described in terms of

Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. [0039] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non- limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as“up to,”“at least,”“greater than,”“less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member.

[0040] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

[0041] Other embodiments are set forth in the following claims.

Claims

WHAT IS CLAIMED IS:

1. A process of producing a polyamide dispersion comprising:

heating a polyamide to above its melting point;

adding an aliphatic surfactant to form a mixture;

under shearing conditions, adding water solution having a basic pH to the mixture to form a sheared mixture; and

cooling the sheared mixture to provide the polyamide dispersion;

wherein the process is conducted in the absence of an organic solvent, and the sheared mixture comprises particles of a polyamide having a volume mean particle size of less than 1 micron.

2. The process of claim 1, wherein the aliphatic surfactant is an anionic surfactant.

3. The process of any one of claims 1-2, wherein the aliphatic surfactant is an anionic, non

aromatic surfactant.

4. The process of any one of claims 1-3, which is an inversion process emulsification.

5. The process of any one of claims 1-3, which is a batch inversion process emulsification.

6. The process of any one of claims 1-5, which is continuous inversion process emulsification.

7. The process of any one of claims 1-6, wherein the aliphatic surfactant is a fatty alcohol ether phosphate surfactant.

8. The process of any one of claims 1-7, wherein the polyamide dispersion comprises polyamide particles having a volume average particle size of 0.5 micron or less.

9. The process of any one of claims 1-8, wherein the polyamide is blended with a resin, prior to emulsification.

10. The process of claim 9, wherein the resin comprises a rosin resin, a hydrocarbon resin, a polyterpene resin, or a terpene phenol resin.

11. The process of any one of claims 1-10, where the polyamide exhibits one or more of the following properties:

a melting point of 90°C to l25°C;

an acid value of less than or equal to 10 mg KOH/gram;

an amine value of less than or equal to 10 mg KOH/gram; and

a melt viscosity at 160° C of 150 to 55,000 mPa-s.

12. The polyamide dispersion produced according to the process of any one of Claims 1-11.