阅读说明：本技术 用于制备聚苯硫醚聚合物颗粒的方法 (Method for producing polyphenylene sulfide polymer particles ) 是由 S.乔尔 K.D.伯兰罕 D.B.罗勒 于 2018-05-14 设计创作，主要内容包括：本发明涉及一种用于制备聚苯硫醚聚合物(PPS)的颗粒的方法,该方法基于使用包含来自二羧酸组分和二醇组分的单元的聚酯聚合物(PE),其中至少2mol.％的该二醇组分是聚(亚烷基二醇)。该方法包括将PPS与该PE熔融共混,将共混物冷却并且通过将该PE溶解在水中来回收这些颗粒。本发明涉及由此获得的PPS颗粒并且涉及这些颗粒在SLS 3D打印、涂料、和热固性树脂增韧中的用途。(The present invention relates to a process for the preparation of particles of polyphenylene sulfide polymer (PPS) based on the use of a polyester Polymer (PE) comprising units from a dicarboxylic acid component and a diol component, wherein at least 2 mol.% of the diol component is a poly (alkylene glycol).)

A method of preparing particles of polyphenylene sulfide polymer (PPS), the method comprising the steps of:

-melt blending a mixture (M) comprising:

a) at least PPS, and

b) at least polyester Polymers (PE) comprising units derived from:

-at least dicarboxylic acid components,

-at least glycol components, wherein at least 2 mol.% of the glycol component is a poly (alkylene glycol) having the formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10,

-processing the mixture (M) into pellets or strands,

-cooling the pellets or strands at a temperature below 80 ℃,

-contacting the pellets or strands with water possibly heated to a temperature of up to 95 ℃,

-recovering the particles, and-recovering the particles,

-optionally drying the particles, and

-optionally sieving the particles.

2. The method of claim 1, wherein at least 50 mol.% of the PPS repeat units are repeat units (R) having the formula (L)_PPS) (mol.% is based on total moles in the PPS polymer):

wherein:

-each R is independently selected from the group consisting of: hydrogen atom, halogen atom, C₁-C₁₂Alkyl radical, C₇-C₂₄Alkylaryl group, C₇-C₂₄Aralkyl radical, C₆-C₂₄Arylene radical, C₁-C₁₂Alkoxy, and C₆-C₁₈Aryloxy group, and

-i is an integer from 0 to 4.

3. The process according to claim 1 or 2, wherein at least 50 mol.% of the recurring units are recurring units (R) of the formula (L'), (R) is_PPS)：

4. The method of any of the preceding claims, wherein the PE further comprises steps from a PE containing at least SO attached to an aromatic core₃Repeating units of a difunctional monomer of the M group, wherein the functional groups are carboxyl groups and wherein M is H or selected from the group consisting of sodium, lithium, and potassiumThe metal ion of (1).

5. The method of any , wherein the PE comprises an element from:

-at least aromatic dicarboxylic acid components,

-at least diol components,

-at least 1 mol.% (based on the total moles in the PE) of a poly (alkylene glycol) having formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10,

-at least aromatic dicarboxylic acids containing at least SO's attached to an aromatic core₃A M group, wherein M is H or a metal ion selected from the group consisting of sodium, lithium, and potassium.

6. The method of any , wherein the PE comprises or consists essentially of an element from the group consisting of:

-an isophthalic acid (I-phthalic acid),

-a diol selected from the group consisting of: ethylene glycol, 1, 4-cyclohexanedimethanol, propane-1, 2-diol, 2-dimethyl-1, 3-propanediol, and mixtures thereof,

-at least 2 mol.% (based on total moles in the PE) of poly (alkylene glycol) of diethylene glycol,

aromatic dicarboxylic acids containing at least SO attached to an aromatic core₃A M group, wherein M is H or a metal ion selected from the group consisting of sodium, lithium, and potassium.

7. The method of any of the preceding claims, wherein the mixture (M) comprises:

a) from 10 to 60 wt.% PPS, and

b) from 40 to 90 wt.% PE.

8. The method of any of the preceding claims, wherein the step of melt blending is performed at a temperature greater than 250 ℃.

9. Particles of polyphenylene sulfide polymer (PPS) obtainable by the process of any of claims 1 to 8, .

10. Particles of polyphenylene sulfide polymer (PPS) produced by a process comprising:

-melt blending the PPS with at least polyester Polymers (PE), the at least polyester Polymers (PE) comprising units from:

-at least dicarboxylic acid components,

-at least glycol components, wherein at least 2 mol.% of the glycol component is a poly (alkylene glycol) having the formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10, and

-dispersing the PE in water.

11. The particles of claim 9 or 10, wherein the particles have a D50 comprised between 5 μ ι η and 100 μ ι η.

12. The particles of any of claims 9-11, wherein the particles have:

-a bulk density of at least 0.45, and

-a tapped density of at least 0.55.

13. The particles of any of claims 9-12, wherein the particles have a circularity and/or circularity of at least 0.75.

14. Use of the particle of any of claims 9-13 for manufacturing a three-dimensional object using a laser sintering based additive manufacturing system.

15. Use of the particles of any of claims 9-13 for toughening a thermosetting resin.

Technical Field

The present invention relates to a process for the preparation of polyphenylene sulfide polymer (PPS) particles, based on the use of a polyester Polymer (PE) comprising units from a dicarboxylic acid component and a diol component, wherein at least 2 mol.% of the diol component is a poly (alkylene glycol).

Background

Additive manufacturing systems are used to print or otherwise build 3D objects through digital blueprints created by Computer Aided Design (CAD) simulation software selective laser sintering ("SLS"), of available additive manufacturing techniques, using electromagnetic radiation from a laser to fuse powdered material into chunks.

The article by Schmid et al (j. mater.res, volume 29, No. 17, 2014) reviews polymers for SLS 3D printing and the properties of their powdered forms. The particles should be spherical to induce free-flowing behavior and be distributed over the powder bed of the printer by a roller or blade system. For operation on SLS equipment, spherical particles with a particle size distribution between 20 and 80 μm are generally optimal.

Spherical polymer powders can be prepared by a process known as granulation, according to which the polymer is dissolved in an organic solvent and subsequently precipitated into a large volume of non-solvent. First, the use of solvents creates a number of environmental and disposal problems. Secondly, this process requires that the polymer be soluble in organic solvents at sufficient levels for efficient processing. While polyphenylene sulfide (PPS) exhibits valuable thermal, mechanical, and chemical resistance properties that make it particularly advantageous for use in SLS 3D printing, PPS is insoluble in most common solvents.

US 8,454,866B 2 discloses the preparation of powders of aliphatic polyamides by forming a melt blend with additives that are block copolymers containing poly (alkylene oxide) blocks the blends are decomposed in water to produce dispersions of polyamide particles, which can then be isolated by filtration and drying.

JP 2014043522 describes the use of melt blending modified PET with PPS to make PPS particles. However, modified PET is insoluble in water heated up to 95 ℃.

It is an object of the present invention to provide methods for preparing spherical PPS particles without the use of organic solvents.

It is another object of the present invention to provide PPS particles that are well suited for SLS 3D printing, coating compositions, and toughening of thermosetting resins.

Disclosure of Invention

The applicants' performance was to identify class of materials, referred to herein as polyester Polymers (PE), which have sufficient thermal stability to melt blend with PPS, which enables the preparation of spherical PPS particles, these polyester polymers being suitable for co-processing with high temperature aromatic PPS polymers.

The process of the present invention is based on melt blending PPS with water-soluble or water-dispersible Polyester (PE) in a manner that produces PPS particles dispersed in a phase comprised of water-soluble or water-dispersible Polyester (PE), for example, by applying mixing energy sufficient to produce discrete particles. The blend is then cooled and the particles recovered by dissolving the polyester in water possibly heated to a temperature of up to 95 ℃.

In the present application:

even if any description described in relation to a specific embodiment is applicable to and interchangeable with other embodiments of the present disclosure;

when elements or components are said to be included in and/or selected from a list of listed elements or components, it is to be understood that in the relevant embodiments explicitly contemplated herein, the element or component can also be any of the individually listed elements or components and can also be selected from a group consisting of any two or more of the explicitly listed elements or components, any element or component listed in a list of elements or components can be omitted from this list, and

any recitation herein of numerical ranges by endpoints includes all numbers subsumed within that range and the endpoints and equivalents of that range.

More specifically, the present invention relates to methods for preparing polyphenylene sulfide polymer (PPS) particles, the method comprising the steps of:

-melt blending a mixture (M) comprising:

a) at least PPS, and

b) at least polyester Polymers (PE) comprising units derived from:

-at least dicarboxylic acid components,

-at least glycol components, wherein at least 2 mol.% of the glycol component is a poly (alkylene glycol) having the formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10,

-processing the mixture (M) into pellets or strands,

optionally cooling the pellets or strands at a temperature below 80 ℃,

-contacting said pellets or strands with water, for example by immersing the pellets or strands in water, possibly heated to a temperature of up to 95 ℃,

recovering the particles, for example separating them from the water,

-optionally drying the particles, and

-optionally sieving the particles.

More generally , the step comprising melt blending the mixture (M) may be performed with any suitable device compatible with the temperatures required to melt the aromatic PPS polymer, such as a worm screw mixer or a blender mixer, e.g., a compounder.

According to a preferred embodiment, the step of melt blending is carried out at a temperature above 280 ℃, such as above 290 ℃, such as above 300 ℃, above 310 ℃.

The step comprising processing the mixture into pellets or strands may be performed by a method of extrusion through a die.

The steps of melt blending and processing into pellets or strands are preferably carried out in an extruder equipped with an extrusion die.

The cooling step is carried out by any suitable means at a temperature below 80 ℃, for example below 50 ℃. Mention may notably be made of air cooling or quenching in a liquid, for example in water.

The stage of contacting the pellets or strands with water may comprise the step of immersing the pellets or strands in water, possibly in water baths (e.g. heated to a temperature of up to 95 ℃). This step allows the polyester to be dissolved for recovery of the PPS particles. The inventors have demonstrated that for sufficient dissolution of the polyester, no acid or base supplementation to the water is required. The present invention advantageously utilizes neutral pH water or tap water.

The steps of the process of the present invention may be carried out batchwise or continuously.

According to an embodiment, the steps of cooling the pellets or strands at a temperature below 80 ℃, for example below 50 ℃, and contacting said pellets or strands with water, for example by immersing the pellets or strands in water (which may possibly be heated to a temperature up to 95 ℃), may be carried out simultaneously in the same apparatus.

The method of the present invention may further comprise an additional step of drying the granules, and/or an additional step of sieving the granules. The drying step may be carried out, for example, in a fluidized bed.

Polyphenylene sulfide polymer (PPS)

According to the invention, "polyphenylene sulfide polymer (PPS)" means a polymer in which at least about 50 mol.% of the recurring units are recurring units (R) having the formula (L)_PPS) Any polymer of (a):

wherein:

-each R is independently selected from the group consisting of: hydrogen atom, halogen atom, C₁-C₁₂Alkyl radical, C₇-C₂₄Alkylaryl group, C_7-C₂₄Aralkyl radical, C₆-C₂₄Arylene radical, C₁-C₁₂Alkoxy, and C₆-C₁₈Aryloxy group, and

-i is an integer from 0 to 4.

In its broadest definition of , the polyphenylene sulfide polymer (PPS) of the present invention may be made of substituted and/or unsubstituted polyphenylene sulfide groups.

According to an embodiment of the present invention, polyphenylene sulfide polymer (PPS) represents a polymer in which at least 50 mol.% of the recurring units are recurring units (R) having the formula (L') (L_PPS) (wherein R is₁Is a hydrogen atom):

according to an embodiment of the present invention, the polyphenylene sulfide polymer is such that at least about 60 mol.%, at least about 70 mol.%, at least about 80 mol.%, at least about 90 mol.%, at least about 95 mol.%, at least about 99 mol.% of the recurring units in the PPS are recurring units (R) having the formula (L) or (L')_PPS)。

The mol.% herein is based on the total moles in the PPS.

According to an embodiment of the invention, the PPS polymer is such that about 100 mol.% of the recurring units are recurring units (R) having the formula (L) or (L'),_PPS). Root of herbaceous plantIn this embodiment, the PPS polymer consists essentially of recurring units (R) having the formula (L) or (L') (L_PPS) And (4) forming.

PPS is notably available under the trade name Solvay specialty polymers USA from Suvier polymers, Inc. (Solvay specialty polymers USA, LLC)

PPS is manufactured and sold.

According to the invention, the melt flow rate of PPS (according to ASTM D1238, procedure B at 316 ℃ under a weight of 5 kg) may be from 50 to 400g/10min, for example from 60 to 300g/10min or from 70 to 200g/10 min.

According to embodiments, the PPS polymer is present in the mixture (M) in an amount of less than 60 wt.%, less than 55 wt.%, less than 50 wt.%, less than 45 wt.%, less than 40 wt.%, less than 35 wt.%, less than 30 wt.%, less than 25 wt.%, or less than 20 wt.%, based on the total weight of the mixture (M).

Polyester Polymer (PE)

According to the invention, "polyester Polymer (PE)" means any polymer comprising units derived from:

-at least dicarboxylic acid components,

-at least glycol components, wherein at least 2 mol.% of the glycol component is a poly (alkylene glycol) having the formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10.

According to an embodiment, the dicarboxylic acid component comprises at least aromatic dicarboxylic acids, for example selected from the group consisting of isophthalic acid (IPA), terephthalic acid (TPA), naphthalenedicarboxylic acids (e.g., naphthalene-2, 6-dicarboxylic acid), 4 '-bibenzoic acid, 2, 5-pyridinedicarboxylic acid, 2, 4-pyridinedicarboxylic acid, 3, 5-pyridinedicarboxylic acid, 2-bis (4-carboxyphenyl) propane, bis (4-carboxyphenyl) methane, 2-bis (4-carboxyphenyl) hexafluoropropane, 2-bis (4-carboxyphenyl) ketone, 4' -bis (4-carboxyphenyl) sulfone, 2-bis (3-carboxyphenyl) propane, bis (3-carboxyphenyl) methane, 2-bis (3-carboxyphenyl) hexafluoropropane, 2-bis (3-carboxyphenyl) ketone, bis (3-carboxyphenoxy) benzene, and mixtures thereof.

According to an embodiment, the glycol component is such that at least 2 mol.% of the glycol component is poly (ethylene glycol) having formula (II):

H(O-CH₂-CH₂)_n-OH

where n varies from 2 to 10.

According to an embodiment, the diol component is such that at least 4 mol.%, at least 10 mol.%, at least 20 mol.%, at least 30 mol.%, at least 40 mol.%, or at least 50 mol.% of the diol component (based on the total moles of the diol component) is a poly (alkylene glycol) having formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10, preferably a poly (ethylene glycol) having the formula (II):

H(O-CH₂-CH₂)_n-OH

where n varies from 2 to 10.

According to another embodiments, the glycol component is such that at least 2 mol.%, at least 4 mol.%, at least 10 mol.%, at least 20 mol.%, at least 30 mol.%, at least 40 mol.%, or at least 50 mol.% of the glycol component (based on the total moles of the glycol component) is of the formula HO-CH₂-CH₂-O-CH₂-CH₂-OH, diethylene glycol.

According to another examples, the glycol component may contain, in addition to the 2 mol.% minimum content of poly (alkylene glycol), at least glycols selected from the group consisting of ethylene glycol, 1, 4-cyclohexanedimethanol, propane-1, 2-diol, 2-dimethyl-1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 2-methyl-1, 5-pentanediol, isosorbide, and 2, 5-bis-hydroxymethyl-tetrahydrofuran.

According to yet another embodiments, the glycol component of the polyester Polymer (PE) consists essentially of:

-a diol selected from the group consisting of: ethylene glycol, 1, 4-cyclohexanedimethanol, propane-1, 2-diol, 2-dimethyl-1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 2-methyl-1, 5-pentanediol, isosorbide and 2, 5-bis-hydroxymethyl-tetrahydrofuran,

-at least 2 mol.% of a poly (ethylene glycol) of formula (I):

H(O-CH₂-CH₂)_n-OH

where n varies from 2 to 10.

According to another examples, the glycol component of the polyester Polymer (PE) consists essentially of:

-a diol selected from the group consisting of: ethylene glycol, 1, 4-cyclohexanedimethanol, propane-1, 2-diol, 2-dimethyl-1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 2-methyl-1, 5-pentanediol, isosorbide and 2, 5-bis-hydroxymethyl-tetrahydrofuran,

at least 2 mol.% of diethylene glycol (based on the total number of glycol components).

According to the present invention, the preferred Polyester (PE) is a polyester further comprising steps from a polyester containing at least SO attached to an aromatic nucleus₃A polyester of repeating units of a difunctional monomer of the M group, wherein the functional group is a carboxyl group and wherein M is H or a metal ion selected from the group consisting of: sodium, potassium, calcium, lithium, magnesium, silver, aluminum, zinc, nickel, copper, palladium, iron, and cesium, preferably selected from the group consisting of sodium, lithium, and potassium. Such preferred polyesters are sometimes referred to as Sulfopolyesters (SPEs). According to this embodiment, the difunctional sulfomonomer may be present in the SPE, for example, at a molar ratio that includes between 1 and 40 mol.%, such as between 5 and 35 mol.%, or between 8 and 30 mol.%, based on the total moles in the SPE (i.e., the total moles of the diacid and diol components if the SPE is composed solely of the diacid and diol components).

According to an embodiment of the invention, the Polyester (PE) comprises units from:

-at least dicarboxylic acid components,

-at least glycol components, wherein at least 2 mol.% of the glycol component is a poly (alkylene glycol) having the formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10,

at least bifunctional monomers containing at least SO's attached to an aromatic nucleus₃A M group, wherein the functional group is a carboxyl group and wherein M is H or a metal ion selected from the group consisting of sodium, lithium, and potassium.

According to another embodiments of the present invention, the Polyester (PE) comprises units from:

-at least aromatic dicarboxylic acid components,

-at least diol components,

-at least 1 mol.% (based on the total moles of units in the PE, e.g. the total number of diacid and diol components if the PE consists solely of diacid and diol units) of a poly (alkylene glycol) having formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10, preferably m is equal to 2 and n is equal to 2,

-at least aromatic dicarboxylic acids containing at least SO's attached to an aromatic core₃A M group, wherein M is H or a metal ion selected from the group consisting of sodium, lithium, and potassium.

According to a preferred embodiment of the invention, the Polyester (PE) comprises or essentially consists of units from:

-aromatic dicarboxylic acids selected from the group consisting of: isophthalic acid (IPA), terephthalic acid (TPA), naphthalenedicarboxylic acids (e.g., naphthalene-2, 6-dicarboxylic acid), 4 '-bibenzoic acid, 2, 5-pyridinedicarboxylic acid, 2, 4-pyridinedicarboxylic acid, 3, 5-pyridinedicarboxylic acid, 2-bis (4-carboxyphenyl) propane, bis (4-carboxyphenyl) methane, 2-bis (4-carboxyphenyl) hexafluoropropane, 2-bis (4-carboxyphenyl) ketone, 4' -bis (4-carboxyphenyl) sulfone, 2-bis (3-carboxyphenyl) propane, bis (3-carboxyphenyl) methane, 2-bis (3-carboxyphenyl) hexafluoropropane, 2-bis (3-carboxyphenyl) ketone, bis (3-carboxyphenoxy) benzene, and mixtures thereof, preferably, the isophthalic acid is an isophthalic acid,

-a diol selected from the group consisting of: ethylene glycol, 1, 4-cyclohexanedimethanol, propane-1, 2-diol, 2-dimethyl-1, 3-propanediol, and mixtures thereof,

at least 1 mol.% (based on the total moles of units in the PE, e.g. the total number of diacid and diol components if the PE consists solely of diacid and diol units) of diethylene glycol,

aromatic dicarboxylic acids (e.g. isophthalic acid, terephthalic acid, 2, 6-naphthalenedicarboxylic acid) containing at least SO's attached to an aromatic nucleus₃A M group, wherein M is H or a metal ion selected from the group consisting of sodium, lithium, and potassium.

According to an embodiment, the PE comprises at least 2 mol.%, at least 4 mol.%, at least 10 mol.%, at least 20 mol.%, at least 30 mol.%, at least 40 mol.%, or at least 50 mol.% of diethylene glycol, based on the total moles of units in the PE (e.g., the total of diacid and diol components if the PE consists solely of diacid and diol units).

Examples of such polyesters are eastman AQ polymers, especially those having a glass transition temperature ranging from about 25 ℃ to about 50 ℃. Most preferred is eastman AQ 38S, a polyester made up of diethylene glycol, Cyclohexanedimethanol (CHDM), isophthalate and sulfoisophthalate units.

The Polyesters (PE) according to the invention may be in the form of salts of sulfonic acids or/and carboxylic acids (more precisely sulfonate-SO)₃ ^-Or carboxylate radical-COO^-) Thus, PE may comprise or several groups (SO)₃ ^-M⁺) And/or (COO)^-M⁺) Wherein M is a metal. According to an embodiment, M is selected from the group consisting of: sodium, potassium or lithium, calcium, magnesium, silver, aluminum, zinc, nickel, copper, palladium, iron, and cesium.

The Polyesters (PE) of the invention can be obtained, for example, by esterification of the components mentioned.

The number average molecular weight of the Polyester (PE) may be between 1,000 and 40,000g/mol, more preferably between 2,000 and 30,000g/mol, as determined by GPC.

According to an embodiment, the PE polymer is present in the mixture (M) in an amount of at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, at least 45 wt.%, at least 50 wt.%, at least 55 wt.%, at least 60 wt.%, at least 65 wt.%, at least 70 wt.%, at least 75 wt.% or at least 80 wt.%, based on the total weight of the mixture (M).

PPS particles

The process of the present invention allows the preparation of PPS particles having regular shape and size.

As used herein, the term "particle" refers to an individualized entity.

The particles may have an average diameter of less than about 200 μm, in some embodiments from about 0.5 μm to about 150 μm, alternatively from about 1 μm to about 100 μm, or from about 1 μm to about 50 μm.

The particles of the invention can be characterized by their particle size distribution D50 (abbreviated as "D50"), which particle size distribution D50 is also referred to as the median diameter or median of the particle size distribution, according to which particle size distribution D50 50% of the particles in the sample are larger and 50% of the particles in the sample are smaller. Particle size analysis may be performed, for example, in a Microtrac with a Microtrac Sample Delivery Controller (SDC)^TMAnd S3500.

According to an embodiment of the invention, the PPS particles have a D50 comprised between 5 μm and 100 μm, for example less than 80 μm and greater than 10 μm or less than 60 μm and greater than 15 μm.

The particles of the present invention can be characterized by their bulk density as well as their tapped density. The bulk density of a powder is the ratio of the mass of an untapped powder sample to its volume (including the contribution of the interparticle void volume). The bulk density may be in grams per milliliter (g/ml) or in grams per cubic centimeter (g/cm)³) And (4) showing. Density measurements may be made, for example, in ^TMQuantachrome Autotap Tapped density analyzerIs carried out in (1).

According to an embodiment of the invention, the PPS particles have:

-a bulk density of at least 0.45, preferably at least 0.47, more preferably at least 0.49, and

-a tapped density of at least 0.55, preferably at least 0.57, more preferably at least 0.59.

The invention also relates to particles of polyphenylene sulfide polymer (PPS) produced by a process comprising:

-melt blending the PPS with at least polyester Polymers (PE), the at least polyester Polymers (PE) comprising units from:

-at least dicarboxylic acid components,

-at least glycol components, wherein at least 2 mol.% of the glycol component is a poly (alkylene glycol) having the formula (I):

H(O-C_mH_2m)_n-OH

wherein m is an integer from 2 to 4 and n varies from 2 to 10, and

-dispersing the PE in water.

All of the above examples regarding the process for preparing particles of polyphenylene sulfide polymer (PPS) are equally applicable in this part of the present description.

The PPS particles obtained by the above described process may also be subjected to at least of the following possible steps:

coating of powder flow enhancers, such as with minerals, for example silica;

-drying under possibly reduced pressure to a temperature of at least 80 ℃, for example at least 90 ℃, for at least 0.5 hours, preferably at least 1 hour; and

-sieving.

The particles of the invention may be substantially spherical, for example having a circularity and/or circularity of at least 0.75, for example at least 0.8 or at least 0.85.

Roundness is defined as a measure of the surface smoothness of a particle and is measured according to the following equation:

circularity is defined as a measure of the spherical shape of a particle and is measured according to the following equation:

the invention also relates to blends of the particles of the polyphenylene sulfide polymer (PPS) of the invention and to a process for preparing such blends.

According to an embodiment, the blend of PPS particles of the invention comprises at least two populations of particles having a D50 in the range of 5 μm to 100 μm, preferably 8 μm to 90 μm, even more preferably 10 μm to 70 μm.

Optional Components

The particles of the invention may comprise various additives such as lubricants, heat stabilizers, light stabilizers, antioxidants, pigments, processing aids, dyes or fillers (e.g. biocompatible fillers such as hydroxyapatite). By way of example, mention may be made in particular of titanium dioxide, zinc oxide, cerium oxide, silicon dioxide or zinc sulphide, these being used as lubricants and/or abrasives. The filler (e.g., reinforcing filler or mineral filler) may be selected from the group consisting of: glass fiber, carbon fiber, talc, wollastonite, calcium carbonate, mica, and the like.

The polymer composition may further comprise a flame retardant such as a halogen and a halogen-free flame retardant.

The principal advantage of the present invention is that is that the optional additives, when present, are located within the PPS particles and are uniformly located within the polymer mass.

Applications of

The particles of the present invention may be used in a variety of applications, notably SLS 3D printing, coating, and thermosetting resin toughening.

Accordingly, the present invention also relates to the use of PPS particles for manufacturing a three-dimensional object using a laser sintering additive manufacturing system.

Examples of the invention

Example 1

Raw material

PPS：

QC160N is commercially available from suwitter polymers, llc of the united states.

PE: istman AQ sulfopolyester commercially available from Eastman corporation (Eastman)^TM48. This PE consists of diethylene glycol, Cyclohexanedimethanol (CHDM), isophthalate and sulfoisophthalate units. According to 1H NMR analysis, the molar concentration of diethylene glycol was 70 mol.%, based on the total moles of glycols (CHMD + diethylene glycol).

PTS: p-toluenesulfonate salt from Spectrum Chemical.

Material processing

Blends were made according to table 1.

15g of each composition was applied to the DSM over a period of 3 minutes

Melt blending in a micro compounder at a specific temperature (see Table 1) and at 150-. Each blend was then processed into strands and then quenched in air until solid. The samples were immersed in water heated to 95 ℃ for 2 hours. The water is then removed. The sample was again immersed in water heated at 90 ℃ for 2 hours.

(example 1, example 2 and example 3) gave polymer powders according to the invention, which were then isolated by filtration and dried in vacuo.

TABLE 1

Scanning Electron Microscope (SEM)

Scanning electron microscopy was used to examine each polymer sample as indicated below. The powder was dispersed on a carbon tape fixed to an aluminum stub and then Sputter coated with AuPd using an Emitech K575x Turbo Sputter Coater (Turbo Coater). Images were recorded using a Hitachi S-4300 cold field emission scanning electron microscope and the average diameter of the images was analyzed for nearly 50 particle images using image analysis software based on image Jv 1.49b Java. A summary of the average particle sizes of the powders estimated from the SEM pictures is presented in table 2.

Fig. 1 is an SEM scan of PPS particles of example 1.

Particle size analysis D50

Particle Size Analysis (PSA) was performed using a Microtrac S3500 with a Microtrac Sample Delivery Controller (SDC).

TABLE 2

	Average diameter (μm)	D50(μm)
			Example 1	8.2±3.5	29.2
Example 2	6.3 Earth 3.7	21.8
			Example 3	2.8±1.4	19.6

The particles of example 1, shown in figure 1, had a circularity of 0.911 ± 0.035 and a circularity of 0.929 ± 0.065.

Example 2

This example is intended to demonstrate that the modified PET component described in JP 2014043522 is insoluble in water heated to 95 ℃.

Raw material

PET：

Polyester EN052 is commercially available from Istman

DMSI: dimethyl 5-sulfoisophthalate sodium salt (98% purity, Mw: 296.23) was commercially available from Alfa Aesar

Preparation method of modified PET

13g PET (90 mol.%) and 2.3g DMSI (10 mol.%) were melt blended in a DSM micro-blender at 310 ℃ during 4 to 8 minutes.

Water solubility test

All samples were exposed to a water bath heated to 80 ℃ for 1 hour under the following conditions: 0.5g of material and 10g of deionized water.

TABLE 3

Example 3

Raw material

PPS：

QC160N is commercially available from suwitter polymers, llc of the united states.

PE: sulfopolyester Istman AQ commercially available from Istman^TM38S. This PE consists of diethylene glycol, Cyclohexanedimethanol (CHDM), isophthalate and sulfoisophthalate units. According to 1H NMR analysis, the molar concentration of diethylene glycol was 80 mol.%, based on the total moles of glycols (CHMD + diethylene glycol).

Material processing

Blends were made according to table 4.

Each composition was melt blended in a ZSK-26 twin screw extruder (cobilong group (Coperion)) under specific conditions as shown in table 4.

Dropping each polymer melt from the extruder die with occasional mixing into barrels of hot water (60 deg.C.) the powder was isolated by vacuum filtration using a Buchner funnel then washed in a Buchner funnel with 2-3L of deionized water the powder was dried at 100 deg.C and reduced pressure

200, spectrochemicals) to give a 1 wt.% mixture.

TABLE 4

Particle size analysis D50

Particle Size Analysis (PSA) was performed using a Microtrac S3500 with a Microtrac Sample Delivery Controller (SDC).

Bulk and tapped density

Using Quantachrome Autotap^TMAnd (3) adopting 500 times of compaction cycles to carry out density by using a compaction density analyzer.

TABLE 5

	D10(μm)	D50(μm)	D90(μm)	Bulk density	Tapped density
						Example 5	4	6	10	0.505	0.664
Example 6	6	41	175	0.499	0.606

Drawings

Fig. 1 is a Scanning Electron Microscope (SEM) image of PPS particles of example 1.