Copolyesters for use in low shear melt applications

Patent metadata

Field	Value
Publication number	US-11427675-B2
Application number	US-201916690314-A
Country	US
Kind code	B2
Filing date	Nov 21, 2019
Priority date	Nov 21, 2019
Publication date	Aug 30, 2022
Grant date	Aug 30, 2022

Abstract

A method of manufacturing a molded article by a low shear manufacturing process that includes: placing a solid polyester in a mold having mold surfaces; heating said polyester until it becomes molten; dispersing said molten polyester over said mold surfaces; solidifying said molten polyester to form a solid molded article; and removing said molded article from said mold; where the polyester is obtained by polymerization of dimethylcyclohexane dicarboxylic acid, cyclohexane dimethanol, polytetramethylene ether glycol and branching agent and has a steep melting curve evidenced by a puddling curve slope of −2 to −10.

First claim

We claim:

1. A method of manufacturing a molded article by a low shear manufacturing process comprising:
a. placing a solid polyester in a mold having mold surfaces;
b. heating said polyester until it becomes molten;
c. dispersing said molten polyester over said mold surfaces;
d. solidifying said molten polyester to form a solid molded article; and
e. removing said molded article from said mold;

wherein said polyester comprises:
a. 99 to 100 mole percent, based on the total molar acid content of the polyester, of a diacid selected from the group consisting of a cyclohexane dicarboxylic acid, a dimethylcyclohexane dicarboxylic acid, and combinations thereof;
b. 75 to 92 mole percent of 1,4-cyclohexane dimethanol and 8 to 25 mole percent of polytetramethylene ether glycol based on the total glycol content of the polyester; and
c. a branching agent in an amount from 0.5 to 1 mole %, said branching agent selected from the group consisting of glycerin, pentaerythritol, phenyl dianhydride, trimellitic anhydride and combinations thereof based on the total molar acid content of the polyester;

wherein said polytetramethylene ether glycol has a number average molecular weight of 600-5000, and
wherein said polyester has a puddling curve slope of −2 to −10 determined by the steepest change in pixel intensity/change in time, wherein pixel intensity is measure by capturing images of a polyester sample from a microscope's objective with a digital camera as the sample is heated from 140° C. at a rate of 10° C./75 seconds using differential scanning calorimetry (DSC).

2. The method of claim 1 wherein said branching agent is
trimelletic anhydride; and
wherein said polyester has a puddling curve slope of −2 to −8.

3. The method of claim 1 wherein said polyester comprises:
a. 80 to 92 mole percent of 1,4-cyclohexane dimethanol and 8 to 20 mole percent of polytetramethylene ether glycol based on the total glycol content of the polyester; and

wherein said polyester has a puddling curve slope of −2 to −8.

4. A method of coating a surface comprising:
a. spreading a powdered solid polyester unto a surface;
b. heating said powdered solid polyester to form a molten polyester coating; and
c. cooling said molten polyester coating to form a solid polyester coating;

wherein said polyester comprises:
a. 99 to 100 mole percent, based on the total molar acid content of the polyester, of a diacid selected from the group consisting of a cyclohexane dicarboxylic acid, a dimethylcyclohexane dicarboxylic acid, and combinations thereof;
b. 75 to 92 mole percent of 1,4-cyclohexane dimethanol and 8 to 25 mole percent of polytetramethylene ether glycol based on the total glycol content of the polyester; and
c. a branching agent in an amount from 0.5 to 1 mole %, said branching agent selected from the group consisting of glycerin, pentaerythritol, phenyl dianhydride, trimellitic anhydride and combinations thereof based on the total molar acid content of the polyester;

wherein said polytetramethylene ether glycol has a number average molecular weight of 600-5000, and
wherein said polyester has a puddling curve slope of −2 to −10 determined by the steepest change in pixel intensity/change in time, wherein pixel intensity is measure by capturing images of a polyester sample from a microscope's objective with a digital camera as the sample is heated from 140° C. at a rate of 10° C./75 seconds using differential scanning calorimetry (DSC).

5. An additive manufacturing method for producing a three-dimensional object, said method comprising the steps of:
a. applying a layer of polyester powder build material onto a target surface;
b. directing electromagnetic wave energy at said powder to form a sintered layer;
c. solidifying said sintered layer; and
d. repeating steps (a) and (b) to form a three-dimensional object in a layerwise fashion;

wherein said polyester comprises the residues of:
i. 99 to 100 mole percent, based on the total molar acid content of the polyester, of a diacid selected from the group consisting of a cyclohexane dicarboxylic acid, a dimethylcyclohexane dicarboxylic acid, and combinations thereof;
ii. 75 to 92 mole percent of 1,4-cyclohexane dimethanol and 8 to 25 mole percent of polytetramethylene ether glycol based on the total glycol content of the polyester; and
iii. a branching agent in an amount from 0.5 to 1 mole %, said branching agent selected from the group consisting of glycerin, pentaerythritol, phenyl dianhydride, trimellitic anhydride and combinations thereof based on the total molar acid content of the polyester;

wherein said polytetramethylene ether glycol has a number average molecular weight of 600-5000, and
wherein said polyester has a puddling curve slope of −2 to −8 determined by the steepest change in pixel intensity/change in time, wherein pixel intensity is measure by capturing images of a polyester sample from a microscope's objective with a digital camera as the sample is heated from 140° C. at a rate of 10° C./75 seconds using differential scanning calorimetry (DSC).

6. The method of claim 3 wherein said polyester has a puddling curve slope of −3.4 to −8.

Assignees

• Eastman Chem Co

Inventors

• Strand Marc Alan
• Weaver Laura Bauerle
• Young Robert Erik

Classifications

• C08J5/00

  Manufacture of articles or shaped materials containing macromolecular substances (manufacture of semi-permeable membranes B01D67/00 - B01D71/00) · CPC title

• C08G63/672

  Dicarboxylic acids and dihydroxy compounds · CPC title

• C08J3/28

  Treatment by wave energy or particle radiation · CPC title

• B29C64/153

  using layers of powder being selectively joined, e.g. by selective laser sintering or melting · CPC title

• C09D167/025

  containing polyether sequences · CPC title