EP2742082A1 - Color management for a polyether polyol product - Google Patents

Color management for a polyether polyol product

Info

Publication number
EP2742082A1
EP2742082A1 EP12745959.2A EP12745959A EP2742082A1 EP 2742082 A1 EP2742082 A1 EP 2742082A1 EP 12745959 A EP12745959 A EP 12745959A EP 2742082 A1 EP2742082 A1 EP 2742082A1
Authority
EP
European Patent Office
Prior art keywords
storage
tanks
product
loading
polyether polyol
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP12745959.2A
Other languages
German (de)
French (fr)
Inventor
Suri N. DORAI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Invista Technologies SARL Switzerland
Original Assignee
Invista Technologies SARL Switzerland
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Invista Technologies SARL Switzerland filed Critical Invista Technologies SARL Switzerland
Publication of EP2742082A1 publication Critical patent/EP2742082A1/en
Withdrawn legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
    • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
    • C08G65/04—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring from cyclic ethers only
    • C08G65/06—Cyclic ethers having no atoms other than carbon and hydrogen outside the ring
    • C08G65/16—Cyclic ethers having four or more ring atoms
    • C08G65/20—Tetrahydrofuran
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G65/00—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule
    • C08G65/02—Macromolecular compounds obtained by reactions forming an ether link in the main chain of the macromolecule from cyclic ethers by opening of the heterocyclic ring
    • C08G65/30—Post-polymerisation treatment, e.g. recovery, purification, drying

Definitions

  • This disclosure relates to the production of polyether polyols. More
  • THF also known as polytetramethylene ether glycols (PTMEG)
  • PTMEG polytetramethylene ether glycols
  • PTMEG can be produced by many known processes. As discussed in U.S. Patent No. 4,120,903, herein incorporated in its entirety by reference, the
  • PTMEG polytetramethylene ether glycol
  • the key parameter that influences the color growth is the presence of oxygen. It has been found that oxygen can be introduced in substantial amounts during the loading and storage process. The oxygen, in synergistic combination with higher than allowable temperatures, can accelerate the oxidation reaction resulting in poor quality as delivered to the customer.
  • the present invention relates to a method of minimizing the color growth in a polyether polyol product during storage, loading and shipping.
  • the color growth is minimized by maintaining the temperature in the storage and loading tanks below a set temperature, replacing substantially all of the air in the storage and loading tanks with inert gas, and providing an anti-air intrusion system within the storage and loading tanks.
  • An embodiment of the present invention comprises the steps of:
  • the temperature of the storage and loading tanks is maintained below 75°C, such as, for example, from about 50°C to less than 75°C.
  • replacing substantially all of the air in the storage and loading tanks prior to filling the tanks with the polyether polyol product is accomplished by a make-up gas system with which inert gas is pumped into the storage and loading tanks through conservation vents.
  • the anti-air intrusion system consists of pumping an inert gas into the storage and loading tanks through conservation vents after filling the tanks with the polyether polyol product.
  • the inert gas used replacing substantially all of the air in the storage and loading tanks prior to filling the tanks with the polyether polyol product is nitrogen.
  • the inert gas used for the anti-air intrusion system is nitrogen.
  • the color growth is maintained below 10 APHA units.
  • the color growth is maintained below 5 APHA units.
  • the polyether polyol product is poly(tetramethylene ether) glycol or a copolymer thereof.
  • the polyether polyol product is combined with a polymerization stabilizer.
  • the polymerization stabilizer is butylated
  • FIG. 1 is a flow chart for an embodiment of the present invention.
  • FIG. 2 is a chart showing the effect of temperature on the color growth of the polyether polyol product.
  • the present invention relates to a method of minimizing the color growth in a polyether polyol product during storage, loading and shipping.
  • the color growth is minimized by maintaining the temperature in the storage and loading tanks below a set temperature, replacing substantially all of the air in the storage and loading tanks with inert gas, and providing an anti-air intrusion system within the storage and loading tanks.
  • PTMEG poly(tetramethylene ether) glycol.
  • PTMEG is also known as polyoxybutylene glycol.
  • THF tetrahydrofuran and includes within its meaning alkyl substituted tetrahydrofuran capable of copolymerizing with THF, for example 2-methyltetrahydrofuran, 3- methyltetrahydrofuran, and 3-ethyltetrahydrofuran.
  • color value refers effectively to yellowness in the visible light spectrum of the product as viewed in total transmission.
  • the polyether polyol is poly(tetramethylene ether) glycol (PTMEG).
  • PTMEG poly(tetramethylene ether) glycol
  • the PTMEG product is to be stored and loaded for transport, wherein oxidation of the PTMEG product would cause unwanted color growth.
  • Fig. 1 depicts a flow chart showing the movement of the PTMEG product before reaching the customer (300).
  • PTMEG manufacturing plants have several storage tanks (100). PTMEG temperatures in these tanks are 80- 1 10°C. Each tank is provided with an internal bayonet steam heater and a powerful centrifugal pump. The purpose of the pump is to not only transfer the PTMEG to the loading and storage tanks (200) but also to allow PTMEG to circulate to ensure that the various batches are adequately mixed to ensure a blend of uniform quality with no stratification in product specification.
  • pumps allow enormous amount of PTMEG to circulate to minimize the blending time. During this process heat is generated which results in increased tank temperature.
  • the PTMEG product temperature is about 80 °C as it leaves the manufacturing process and the temperature is increased further which is attributed (1 ) primarily to the circulation pump and (2) secondarily to the malfunctioning of the electric trace overheating the content.
  • the PTMEG product is then pumped into the storage and loading tanks (200).
  • the temperature of the storage and loading tanks is maintained below 75°C, such as, for example, from about 50°C to below 75°C.
  • the product can be cooled prior to entering the storage and loading tanks by using conventional manufacturing techniques, such a water cooler. After the PTMEG product has been pumped into the storage and loading tanks, the product is considered to be a homogenous blend of uniform quality. Therefore, circulation pumps are only used sparingly at this point, primarily to transfer the PTMEG product for shipping. This prevents the temperature of the PTMEG product from rising above 75°C.
  • substantially all of the air in the storage and loading tanks (200) is replaced with an inert gas.
  • the air in the storage tanks is replaced by a make-up gas system with which inert gas is pumped into the storage and loading tanks through conservation vents.
  • the storage and loading tanks (200) are checked to ensure the oxygen level is below 2%, such as, for example, from about 0 to below 2%.
  • an anti-air intrusion system is provided within the storage and loading tanks (200) to prevent additional oxygen from entering.
  • the anti-air intrusion system consists of pumping an inert gas into the storage and loading tanks through conservation vents after filling the tanks with the PTMEG product.
  • the storage and loading tanks (200) are checked to ensure the oxygen level is still below 2% before shipping to customers (300).
  • the make-up gas used to replace the air in the storage and loading tanks and for the anti-air intrusion system can be any inert gas void of oxygen.
  • the inert gas is nitrogen.
  • the color growth is measured by determining a first color value of the polyol product prior to entering the storage and loading tanks, determining a second color value after the polyol product has been pumped into the storage and loading tanks, and measuring the difference between the first color value and the second color value.
  • color value refers effectively to yellowness in the visible light spectrum of the product as viewed in total transmission.
  • the color value is indicated by an APHA index that is measured according to the method described in ASTM 1209.
  • ASTM 1209 the measurement of and the color index assigned is based upon the ASTM D1209 method which correlates to the physical APHA/PtCo Color Index described in the ASTM method.
  • the APHA/PtCo color index is
  • the color growth of the polyol product is maintained below 10 APHA units. In another embodiment of the present invention, the color growth of the polyol product is maintained below 5 APHA units.
  • the polyether polyol product is combined with a polymerization stabilizer.
  • the polymerization stabilizer is butylated hydroxytoluene (BHT).
  • Example 1 illustrates the increase of color growth of the polyether polyol product at increased oxygen levels.
  • 100-200 gram samples of 1000-2000 grade Terathane T PTMEG product were taken from the manufacturing process via a DOPAK TM sampler. The samples were heated in an oven to 90 °C.
  • oxygen was prevented from entering by the use of nitrogen padding.
  • the color value of the sample was tested over a 24 hour period using the HunterLab ColorQuest II spectro-colorimeter described above. After 24 hours of testing, the first sample showed a mean color growth of 1.86 AHPA units.
  • a second sample of the PTMEG was taken and was exposed to the atmosphere to allow oxygen containing air to enter. After 24 hours of testing, the mean color growth of this sample was found to be 10.57 AHPA units. Consequently, the effect of maintaining low oxygen levels in the PTMEG product to prevent color growth was clearly shown.
  • Example 2 illustrates the increase of color growth of the polyether polyol product at increased temperature levels.
  • 100-200 gram samples of 000-2000 grade TerathaneTM PTMEG product were taken from the manufacturing process via a DOPAKTM sampler. The samples were exposed to the atmosphere to allow miminal levels of oxygen to enter. The samples were then tested at various temperatures to show the effect on color growth. The results of the test are
  • a method for minimizing color growth in a polyether polyol product during storage and loading comprises the following steps. Initially, a polyether polyol product to be stored and loaded for transport is provided, wherein oxidation of the polyether polyol product would cause unwanted color growth. The system of storage and loading tanks are maintained below a set temperature to prevent oxidation of the polyether polyol product. Prior to filling the tanks with the polyether polyol product, substantially all of the air in the storage and loading tanks is replaced with inert gas. Finally, an anti- air intrusion system is provided within the storage and loading tanks to prevent additional air from entering.
  • Example 3 The process of Example 3 is repeated with additional steps. In this example, the temperature of the storage and loading tanks is maintained below 75°C.
  • Example 4 The process of Example 4 is repeated with additional steps.
  • replacing substantially all of the air in the storage and loading tanks prior to filling the tanks with the polyol product is accomplished by a make-up gas system with which inert gas is pumped into the storage and loading tanks through conservation vents.
  • Example 5 The process of Example 5 is repeated with additional steps.
  • the anti-air intrusion system consists of pumping an inert gas into the storage and loading tanks through conservation vents after filling the tanks with the polyol product.
  • Example 5 The process of Example 5 or Example 6 is repeated with additional steps.
  • the inert gas is nitrogen.
  • Example 9 The process of Example 7 is repeated with additional steps. In this example, the color growth of the polyether polyol product is maintained below 0 APHA units. Example 9
  • Example 8 The process of Example 8 is repeated with additional steps. In this example, the color growth of the polyether polyol product is maintained below 5 APHA units.
  • Example 9 The process of Example 9 is repeated with additional steps.
  • the polyether polyol product is poly(tetramethylene ether) glycol or a copolymer thereof.
  • Example 10 The process of Example 10 is repeated with additional steps.
  • the polyether polyol product is combined with a polymerization stabilizer.
  • Example 11 The process of Example 11 is repeated with additional steps.
  • the polymerization stabilizer is butylated hydroxytoluene (BHT).
  • ratios, concentrations, amounts, and other numerical data may be expressed herein in a range format. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.
  • a concentration range of "about 0.1 % to about 5%” should be interpreted to include not only the explicitly recited concentration of about 0.1 wt% to about 5 wt%, but also the individual concentrations (e.g., 1 %, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1 %, 2.2%, 3.3%, and 4.4%) within the indicated range.
  • the term “about” can include ⁇ 1 %, ⁇ 2%, ⁇ 3%, ⁇ 4%, ⁇ 5%, ⁇ 8%, or ⁇ 10%, of the numerical value(s) being modified.
  • the phrase "about 'x' to 'y'" includes “about 'x' to about y".

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Polyethers (AREA)

Abstract

A method for minimizing color growth in a polyether polyol product during storage and loading comprising the steps of providing a polyether polyol product to be stored and loaded for transport, wherein oxidation of the polyether polyol product would cause unwanted color growth and providing a system of storage and loading tanks and maintaining the storage and loading tanks below a set temperature to prevent oxidation of the polyether polyol product. Prior to filling the tanks with the polyether polyol product, substantially all of the air in the storage and loading tanks is replaced with an inert gas. After filling the tanks with the polyether polyol product, an anti-air intrusion system is provided to prevent additional air from entering the storage and loading tanks.

Description

COLOR MANAGEMENT FOR A POLYETHER POLYOL PRODUCT
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of priority from U.S. Provisional Application No. 61/521 ,881 filed 10 August 2011 and Chinese Patent Application No. 201110333757.9 filed 28 October 2011. This application hereby incorporates both applications in their entirety.
FIELD OF THE INVENTION
[0002] This disclosure relates to the production of polyether polyols. More
specifically, it relates to minimizing color growth in a polyether polyol product during storage, loading and shipping.
BACKGROUND OF THE INVENTION
[0003] Homopolymers of THF, also known as polytetramethylene ether glycols (PTMEG), are well known for use in spandex, polyurethanes and other elastomers. These homopolymers impart superior mechanical and dynamic properties to
polyurethane elastomers, fibers and other forms of final products.
[0004] PTMEG can be produced by many known processes. As discussed in U.S. Patent No. 4,120,903, herein incorporated in its entirety by reference, the
polymerization process of utilizing tetrahydrofuran (THF) to manufacture
polytetramethylene ether glycol (PTMEG) by passing through the intermediate PTMEA (i.e., PTMEG diacetate) has been commercially practiced since about 1997.
[0005] One common problem in the shipping, loading and storage of the PTMEG product is that many operational parameters cause color growth in the polymer product. If the color growth of the PTMEG product is significantly higher after storage than during the manufacturing process, the product may no longer meet customer standards.
[0006] Therefore, there is a need for a method of minimizing the color growth in a polyether polyol product during storage, loading and shipping. SUMMARY OF THE INVENTION
[0007] The key parameter that influences the color growth is the presence of oxygen. It has been found that oxygen can be introduced in substantial amounts during the loading and storage process. The oxygen, in synergistic combination with higher than allowable temperatures, can accelerate the oxidation reaction resulting in poor quality as delivered to the customer.
[0008] Accordingly, the present invention relates to a method of minimizing the color growth in a polyether polyol product during storage, loading and shipping. The color growth is minimized by maintaining the temperature in the storage and loading tanks below a set temperature, replacing substantially all of the air in the storage and loading tanks with inert gas, and providing an anti-air intrusion system within the storage and loading tanks. An embodiment of the present invention comprises the steps of:
(a) providing a polyether polyol product to be stored and loaded for transport, wherein oxidation of the polyether polyol product would cause unwanted color growth;
(b) providing a system of storage and loading tanks and maintaining the storage and loading tanks below a set temperature to prevent oxidation of the polyether polyol product;
(c) replacing substantially all of the air in the storage and loading tanks with inert gas prior to filling the tanks with the polyether polyol product; and
(d) providing an anti-air intrusion system within the storage and loading tanks to prevent additional air from entering.
[0009] In another embodiment, the temperature of the storage and loading tanks is maintained below 75°C, such as, for example, from about 50°C to less than 75°C.
[0010] In another embodiment, replacing substantially all of the air in the storage and loading tanks prior to filling the tanks with the polyether polyol product is accomplished by a make-up gas system with which inert gas is pumped into the storage and loading tanks through conservation vents.
[0011] In another embodiment, the anti-air intrusion system consists of pumping an inert gas into the storage and loading tanks through conservation vents after filling the tanks with the polyether polyol product. [0012] In another embodiment, the inert gas used replacing substantially all of the air in the storage and loading tanks prior to filling the tanks with the polyether polyol product is nitrogen.
[0013] In another embodiment, the inert gas used for the anti-air intrusion system is nitrogen.
[0014] In another embodiment, the color growth is maintained below 10 APHA units.
[0015] In another embodiment, the color growth is maintained below 5 APHA units.
[0016] In another embodiment, the polyether polyol product is poly(tetramethylene ether) glycol or a copolymer thereof.
[0017] In another embodiment, the polyether polyol product is combined with a polymerization stabilizer.
[0018] In another embodiment, the polymerization stabilizer is butylated
hydroxytoluene (BHT).
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a flow chart for an embodiment of the present invention.
[0020] FIG. 2 is a chart showing the effect of temperature on the color growth of the polyether polyol product.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention relates to a method of minimizing the color growth in a polyether polyol product during storage, loading and shipping. The color growth is minimized by maintaining the temperature in the storage and loading tanks below a set temperature, replacing substantially all of the air in the storage and loading tanks with inert gas, and providing an anti-air intrusion system within the storage and loading tanks.
[0022] All patents, patent applications, test procedures, priority documents, articles, publications, manuals, and other documents cited herein are fully incorporated by reference to the extent such disclosure is not inconsistent with this invention and for all jurisdictions in which such incorporation is permitted. [0023] The term "polymerization", as used herein, unless otherwise indicated, includes the term "copolymerization" within its meaning.
[0024] The term "PTMEG", as used herein, unless otherwise indicated, means poly(tetramethylene ether) glycol. PTMEG is also known as polyoxybutylene glycol.
[0025] The term "THF", as used herein, unless otherwise indicated, means tetrahydrofuran and includes within its meaning alkyl substituted tetrahydrofuran capable of copolymerizing with THF, for example 2-methyltetrahydrofuran, 3- methyltetrahydrofuran, and 3-ethyltetrahydrofuran.
[0026] The term "color value", as used herein, unless otherwise indicated, refers effectively to yellowness in the visible light spectrum of the product as viewed in total transmission.
[0027] A method for minimizing the color growth in a polyether polyol product during storage and loading is herein described. In the embodiment herein described the polyether polyol is poly(tetramethylene ether) glycol (PTMEG). The PTMEG product is to be stored and loaded for transport, wherein oxidation of the PTMEG product would cause unwanted color growth. Fig. 1 depicts a flow chart showing the movement of the PTMEG product before reaching the customer (300). Typically, PTMEG manufacturing plants have several storage tanks (100). PTMEG temperatures in these tanks are 80- 1 10°C. Each tank is provided with an internal bayonet steam heater and a powerful centrifugal pump. The purpose of the pump is to not only transfer the PTMEG to the loading and storage tanks (200) but also to allow PTMEG to circulate to ensure that the various batches are adequately mixed to ensure a blend of uniform quality with no stratification in product specification.
[0028] Consequently, pumps allow enormous amount of PTMEG to circulate to minimize the blending time. During this process heat is generated which results in increased tank temperature. The PTMEG product temperature is about 80 °C as it leaves the manufacturing process and the temperature is increased further which is attributed (1 ) primarily to the circulation pump and (2) secondarily to the malfunctioning of the electric trace overheating the content.
[0029] The PTMEG product is then pumped into the storage and loading tanks (200). In accord with the present invention, the temperature of the storage and loading tanks is maintained below 75°C, such as, for example, from about 50°C to below 75°C. The product can be cooled prior to entering the storage and loading tanks by using conventional manufacturing techniques, such a water cooler. After the PTMEG product has been pumped into the storage and loading tanks, the product is considered to be a homogenous blend of uniform quality. Therefore, circulation pumps are only used sparingly at this point, primarily to transfer the PTMEG product for shipping. This prevents the temperature of the PTMEG product from rising above 75°C.
[0030] Further in accord herewith, and prior to filling the tanks with the PTMEG product, substantially all of the air in the storage and loading tanks (200) is replaced with an inert gas. The air in the storage tanks is replaced by a make-up gas system with which inert gas is pumped into the storage and loading tanks through conservation vents. Prior to loading the PTMEG product, the storage and loading tanks (200) are checked to ensure the oxygen level is below 2%, such as, for example, from about 0 to below 2%.
[0031] After the PTMEG product is pumped into the storage and loading tanks (200), an anti-air intrusion system is provided within the storage and loading tanks (200) to prevent additional oxygen from entering. The anti-air intrusion system consists of pumping an inert gas into the storage and loading tanks through conservation vents after filling the tanks with the PTMEG product. After loading, the storage and loading tanks (200) are checked to ensure the oxygen level is still below 2% before shipping to customers (300).
[0032] The make-up gas used to replace the air in the storage and loading tanks and for the anti-air intrusion system can be any inert gas void of oxygen. In an exemplary embodiment of the present invention, the inert gas is nitrogen.
[0033] The color growth is measured by determining a first color value of the polyol product prior to entering the storage and loading tanks, determining a second color value after the polyol product has been pumped into the storage and loading tanks, and measuring the difference between the first color value and the second color value.
[0034] The term "color value", refers effectively to yellowness in the visible light spectrum of the product as viewed in total transmission. The color value is indicated by an APHA index that is measured according to the method described in ASTM 1209. Herein the measurement of and the color index assigned is based upon the ASTM D1209 method which correlates to the physical APHA/PtCo Color Index described in the ASTM method. As known to the skilled person, the APHA/PtCo color index is
meaningful where a clear liquid having a slight color similar in hue to a PtCo standard solution is concerned.
[0035] In an exemplary embodiment of the present invention, the color growth of the polyol product is maintained below 10 APHA units. In another embodiment of the present invention, the color growth of the polyol product is maintained below 5 APHA units.
[0036] In an exemplary embodiment of the present invention, the polyether polyol product is combined with a polymerization stabilizer. In another embodiment of the present invention, the polymerization stabilizer is butylated hydroxytoluene (BHT).
Examples
[0037] The following Examples demonstrate the present invention and its capability for use. The invention is capable of other and different embodiments, and its several details are capable of modifications in various apparent respects, without departing from the scope and spirit of the present invention. Accordingly, the Examples are to be regarded as illustrative in nature and non-limiting.
[0038] Measurement of all samples herein is provided using HunterLab ColorQuest II spectro-colorimeter with HunterLab software (Hunter Associates Laboratory, Inc., 11491 Sunset Hills Road, Reston, VA 20190). The color value from the HunterLab ColorQuest II instrument is expressed as a number representing APHA color in the range of 1 APHA to 400 APHA. The measurement accuracy (according to HunterLab) is +1 APHA unit centered about an APHA of 300. At the extremes (e.g., APHA < 10 and APHA > 490) the accuracy 5% relative (according to HunterLab). All APHA measurements are made versus a standard Pt Co (Platinum-Cobalt) Color Standard Solution, No. 500 APHA Color. Example 1
[0039] Example 1 illustrates the increase of color growth of the polyether polyol product at increased oxygen levels. 100-200 gram samples of 1000-2000 grade Terathane T PTMEG product were taken from the manufacturing process via a DOPAK TM sampler. The samples were heated in an oven to 90 °C. In a first sample, oxygen was prevented from entering by the use of nitrogen padding. The color value of the sample was tested over a 24 hour period using the HunterLab ColorQuest II spectro-colorimeter described above. After 24 hours of testing, the first sample showed a mean color growth of 1.86 AHPA units. A second sample of the PTMEG was taken and was exposed to the atmosphere to allow oxygen containing air to enter. After 24 hours of testing, the mean color growth of this sample was found to be 10.57 AHPA units. Consequently, the effect of maintaining low oxygen levels in the PTMEG product to prevent color growth was clearly shown.
Example 2
[0040] Example 2 illustrates the increase of color growth of the polyether polyol product at increased temperature levels. As in Example 1 , 100-200 gram samples of 000-2000 grade Terathane™ PTMEG product were taken from the manufacturing process via a DOPAK™ sampler. The samples were exposed to the atmosphere to allow miminal levels of oxygen to enter. The samples were then tested at various temperatures to show the effect on color growth. The results of the test are
summarized in Fig. 2. As shown in Fig. 2, at temperatures above 75°C, the samples showed a significant increase in color growth. Therefore, it was determined that to prevent an increase in color value, it is desirable to maintain the PTMEG product at or below 75°C.
Example 3
[0041] A method for minimizing color growth in a polyether polyol product during storage and loading comprises the following steps. Initially, a polyether polyol product to be stored and loaded for transport is provided, wherein oxidation of the polyether polyol product would cause unwanted color growth. The system of storage and loading tanks are maintained below a set temperature to prevent oxidation of the polyether polyol product. Prior to filling the tanks with the polyether polyol product, substantially all of the air in the storage and loading tanks is replaced with inert gas. Finally, an anti- air intrusion system is provided within the storage and loading tanks to prevent additional air from entering.
Example 4
[0042] The process of Example 3 is repeated with additional steps. In this example, the temperature of the storage and loading tanks is maintained below 75°C.
Example 5
[0043] The process of Example 4 is repeated with additional steps. In this example, replacing substantially all of the air in the storage and loading tanks prior to filling the tanks with the polyol product is accomplished by a make-up gas system with which inert gas is pumped into the storage and loading tanks through conservation vents.
Example 6
[0044] The process of Example 5 is repeated with additional steps. In this example, the anti-air intrusion system consists of pumping an inert gas into the storage and loading tanks through conservation vents after filling the tanks with the polyol product.
Example 7
[0045] The process of Example 5 or Example 6 is repeated with additional steps. In this example, the inert gas is nitrogen.
Example 8
[0046] The process of Example 7 is repeated with additional steps. In this example, the color growth of the polyether polyol product is maintained below 0 APHA units. Example 9
[0047] The process of Example 8 is repeated with additional steps. In this example, the color growth of the polyether polyol product is maintained below 5 APHA units.
Example 10
[0048] The process of Example 9 is repeated with additional steps. In this example, the polyether polyol product is poly(tetramethylene ether) glycol or a copolymer thereof.
Example 11
[0049] The process of Example 10 is repeated with additional steps. In this example, the polyether polyol product is combined with a polymerization stabilizer.
Example 12
[0050] The process of Example 11 is repeated with additional steps. In this example, the polymerization stabilizer is butylated hydroxytoluene (BHT).
[0051] It should be noted that ratios, concentrations, amounts, and other numerical data may be expressed herein in a range format. It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a concentration range of "about 0.1 % to about 5%" should be interpreted to include not only the explicitly recited concentration of about 0.1 wt% to about 5 wt%, but also the individual concentrations (e.g., 1 %, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1 %, 2.2%, 3.3%, and 4.4%) within the indicated range. The term "about" can include ±1 %, ±2%, ±3%, ±4%, ±5%, ±8%, or ±10%, of the numerical value(s) being modified. In addition, the phrase "about 'x' to 'y'" includes "about 'x' to about y".
[0052] While the illustrative embodiments of the invention have been described with particularity, it will be understood that the invention is capable of other and different embodiments and that various other modifications will be apparent to and may be readily made by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is not intended that the scope of the claims hereof be limited to the examples and descriptions set forth herein but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present disclosure, including all features which would be treated as equivalents thereof by those skilled in the art to which the invention pertains.

Claims

CLAIMS What is claimed:
1. A method for minimizing color growth in a polyether poiyol product during storage and loading comprising the steps of:
(a) providing a polyether poiyol product to be stored and loaded for transport,
wherein oxidation of the polyether poiyol product would cause unwanted color growth;
(b) providing a system of storage and loading tanks and maintaining the storage and loading tanks below a set temperature to prevent oxidation of the polyether poiyol product;
(c) replacing substantially all of the air in the storage and loading tanks with inert gas prior to filling the tanks with the polyether poiyol product; and
(d) providing an anti-air intrusion system within the storage and loading tanks to
prevent additional air from entering.
2. The method of claim 1 wherein the temperature of the storage and loading tanks is maintained below 75°C.
3. The method of claim 1 wherein replacing substantially all of the air in the storage and loading tanks prior to filling the tanks with the poiyol product is accomplished by a make-up gas system with which inert gas is pumped into the storage and loading tanks through conservation vents.
4. The method of claim 1 wherein the anti-air intrusion system consists of pumping an inert gas into the storage and loading tanks through conservation vents after filling the tanks with the poiyol product.
5. The method of claim 3 or 4 wherein the inert gas is nitrogen.
6. The method of claim 1 wherein the color growth of the polyether polyol product is maintained below 10 APHA units.
7. The method of claim 6 wherein the color growth of the polyether polyol product is maintained below 5 APHA units.
8. The method of claim 1 wherein the polyether polyol product is poly(tetramethylene ether) glycol or a copolymer thereof.
9. The method of claim 1 wherein the polyether polyol product is combined with a polymerization stabilizer.
10. The method of claim 9 wherein the polymerization stabilizer is butylated
hydroxytoluene.
EP12745959.2A 2011-08-10 2012-07-31 Color management for a polyether polyol product Withdrawn EP2742082A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US201161521881P 2011-08-10 2011-08-10
CN2011103337579A CN102923387A (en) 2011-08-10 2011-10-28 Color management for a polyether polyol product
PCT/US2012/048915 WO2013022644A1 (en) 2011-08-10 2012-07-31 Color management for a polyether polyol product

Publications (1)

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EP2742082A1 true EP2742082A1 (en) 2014-06-18

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EP12745959.2A Withdrawn EP2742082A1 (en) 2011-08-10 2012-07-31 Color management for a polyether polyol product

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EP (1) EP2742082A1 (en)
JP (1) JP2014521815A (en)
KR (1) KR20140064837A (en)
CN (1) CN102923387A (en)
WO (1) WO2013022644A1 (en)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4120903A (en) 1977-03-30 1978-10-17 E. I. Du Pont De Nemours And Company Method for preparing poly(tetramethylene ether) glycol
DE19715831A1 (en) * 1997-04-16 1998-10-22 Basf Ag Process for decolorization of polymers or copolymers of tetrahydrofuran
DE10032266A1 (en) * 2000-07-03 2002-01-17 Basf Ag Improved process for the one-step production of polytetrahydrofuran and tetrahydrofuran copolymers
DE10223067A1 (en) * 2002-05-24 2003-12-11 Basf Ag Process for the preparation of polytetrahydrofuran with low color numbers
DE102004002094A1 (en) * 2004-01-14 2005-08-04 Basf Ag Mixtures containing polytetrahydrofuran and stabilizer

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2013022644A1 *

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CN102923387A (en) 2013-02-13
WO2013022644A1 (en) 2013-02-14
KR20140064837A (en) 2014-05-28

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