CA1149989A - Unsaturated polyesters prepared from a dicarboxylic acid and dibromoneopentyl glycol - Google Patents
Unsaturated polyesters prepared from a dicarboxylic acid and dibromoneopentyl glycolInfo
- Publication number
- CA1149989A CA1149989A CA000365960A CA365960A CA1149989A CA 1149989 A CA1149989 A CA 1149989A CA 000365960 A CA000365960 A CA 000365960A CA 365960 A CA365960 A CA 365960A CA 1149989 A CA1149989 A CA 1149989A
- Authority
- CA
- Canada
- Prior art keywords
- acid
- sulfonic acid
- glycol
- reaction
- aryl sulfonic
- 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.)
- Expired
Links
Landscapes
- Macromonomer-Based Addition Polymer (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
ABSTRACT
Unsaturated esters can be prepared from dicarboxylic acids and dibromoneopentyl glycol with improved resin color in a shorter reacting time with a net energy saving by the process using an aryl sul-fonic acid as the esterification catalyst and following completion of the reaction neutralizing the acid catalyst.
Unsaturated esters can be prepared from dicarboxylic acids and dibromoneopentyl glycol with improved resin color in a shorter reacting time with a net energy saving by the process using an aryl sul-fonic acid as the esterification catalyst and following completion of the reaction neutralizing the acid catalyst.
Description
9~39 ~1--UNSATURATED POLYESTERS PREPARED
FROM A DICARBOXYLIC ACID AND
DIBROMONEOPENTYL GLYCOL
Unsaturated polyester resins are convention-ally prepared by reacting dibasic acids; i.e., phthalic anhydride, maleic anhydride, etc., and difunctional alco-hols; i.e., ethylene glycol, propylene glycol, etc., in stainless steel reactors at temperatures between 170C--200C. Corrosion of stainless steel is slow enough in thèse systems that it does not have an adverse effect on either reactor life or resin color.
Synthesis of unsaturated polyester resins such as those described in U.S. Patent 3,507,933, i.e., fire retardant resins prepared from phthalic anhydride, maleic ànhydride, and dibromoneopentyl glycol, results in corro-sion problems when carried out in stainless steel reactors, and this in turn :Leads to color problems.
The use of sulfuric acid and sulfonic acids as catalysts for polyesterification reactions using saturated dibasic acids are known in the prior art, e.g., P. J. Flory disclosed the use of p-toluene sulfonic acid (p-TSA) as a catalyst for the reaction of adipic acid and ethylene gly-col in 1939. Later attempts to use strong acid catalysts 28,327A-F -1- ~
38~
FROM A DICARBOXYLIC ACID AND
DIBROMONEOPENTYL GLYCOL
Unsaturated polyester resins are convention-ally prepared by reacting dibasic acids; i.e., phthalic anhydride, maleic anhydride, etc., and difunctional alco-hols; i.e., ethylene glycol, propylene glycol, etc., in stainless steel reactors at temperatures between 170C--200C. Corrosion of stainless steel is slow enough in thèse systems that it does not have an adverse effect on either reactor life or resin color.
Synthesis of unsaturated polyester resins such as those described in U.S. Patent 3,507,933, i.e., fire retardant resins prepared from phthalic anhydride, maleic ànhydride, and dibromoneopentyl glycol, results in corro-sion problems when carried out in stainless steel reactors, and this in turn :Leads to color problems.
The use of sulfuric acid and sulfonic acids as catalysts for polyesterification reactions using saturated dibasic acids are known in the prior art, e.g., P. J. Flory disclosed the use of p-toluene sulfonic acid (p-TSA) as a catalyst for the reaction of adipic acid and ethylene gly-col in 1939. Later attempts to use strong acid catalysts 28,327A-F -1- ~
38~
-2-in the preparation of unsaturated polyester resins ha~e been less than suceessful. Weakly acidic or basic cata- --lysts are usually required for reactions in~olving ali-phatic diols in order to prevent dehydration to ether or olefin. It has also been pointed out that acid catalysts such as sulfuric acid or p-TSA, while increasing the rate of bo-th esterification and isomerization, usually cause color formation and other detrimental side reactions.
Some of these adverse reactions caused by the presence of sulfuric, or sulfonic acids, include premature gelation of the styrenated and unstyrenated resins and the loss of glycol from the cook due to the formation of vola-tile ethers. It has been shown that as little as 50 ppm of sulfuric acid will catalyze the formation of ethers from aliphatic diols at polyester reaction temperatures.
The present invention is a process for prepar-ing unsaturated polyesters by reacting an unsaturated dicarboxylic acid with a polyol composed at least in part with dibromoneopentyl glycol wherein the catalyst employed is an aryl sulfonic acid and followi~g completion of the reaction there is added a su~`ficient amount of an acid #CaVenger to neutralize s~id sulfonic acid.
An unsaturated polyest2r is a condensation polymer produced by condensing approximately equimolar proportions of at least one dicarboxylic acid, ~t least a portion of which contains ethylenic unsaturation, with at le2st one pGlyol, which for purposes of this inven-tion, must be made up at least in part of di~romoneopen-tyl glycol. Examples of such unsaturated acids include maleic, fumaric and itaconic acids. Th~ ~emainder, if 28,327A F ~
9~389 _3_ any, of the dicarboxyllc acids are usually either satu-rated nonTal aliphatics, such as adipic acid, succinic acid, or aromatic diacids, such as phthalic acid or iso-phthalic acid. The tPrm dicarboxylic acid, as used herein, S is intended to e~brace the anhydride as well.
The unsaturated acid provides the unsaturation needed for curing the resin. Therefore, the actual ratio of unsaturated acid to saturated acid will be dictated by the deg,ee of cross-linking desired in the cured product.
That degree of cross-linking may be predetermined by sim-ple preliminary experiments as is standard in the poly-ester art.
The polyol to be used is dibromoneopentyl gly-col. Other no~halogenated glycols may ~e used in small amounts without affecting the inventive concept. However, when using aryl sulfonic acids as the esterification cata-lysts, those nonhalogenated glycols form ethers and other undesirable by-products.~ The preserlt invention appears to be singularly well adapted or use with dibromoneopen-tyl glycol which must form the substantial majority ofthe polyol.
The acid scaveng~r to be use~ in the process is any compound that will neutralize -t~ acid catalyst through formation of a salt, ester, amine salt or by other means. Typical of such scavengers are the oxirane compounds, such as epichlorohydrin, the diglycidyl ether of a polyol as, for example, a diglycidyl ether of an aliphatic glycol having an epoxy equivalent weight of 175-205, and other epoxy compounds; oxetane compoun~s 28,327A-F -3-9~38~
such as bis-2,2-(dibromonethyl)oxetane; amines such as diethanolamine or triethanolamine; soluble salts of weak acids such as sodium acetate or hypophosphorous acid.
The esterification catalyst is an aryl sul-fonic acid. Typical of those acids are benzene sulfonicacid and p-toluene sulfonic acid. The amount of catalyst can vary between about 0.OS and 3 percent by weight of the reactants. Preferably, the amount is between 0.1 and 0.4 weight percent.
The polyester is made in generally conventional manner except as otherwise described herein. The acid and dibromoneopentyl glycol are introduced into a suitable esterification reaction vessel equipped with means for removing water of esterification suitably as it is ormed in the reaction. T~e reactants are blanketed with an inert atmospher~, preferably nitrogen gas, then agitated and heated to effect the reaction for a desired period of time. The reaction temperature can range from about 100C to 200C, preferably from 135C to 155C. The exact reaction time will depend on the resin ormulation, the amount of catalyst, the reaction temperature and pressure and the inert gas sparge rate.
The degree of reaction is conveniently deter-mined by measuring the acid number or by measuring the amount of water liberated in the reaction. The reaction is discontinued when the product has a desired acid num-ber, e.g., an acid number of 40 or below. After the reaction has been carried to the desired degree of com-pletion, the acid scavenger is added.
28,327A-F -4-~` , .
~ 9~8~
The resin is then recovered and blended with an ethyleni~all~- unsaturated monomer copolymerizable with the unsaturated polyester polymers to form a blend wherein the weight ratio of polyester to monomer is in the range 5 from about 4:1 to about 1;2. Such ethylenically unsatu-rated monomers are well-known and include styrene, chloro-styrene, vinyl toluene, divinylbenzene, dicyclopentadiene alkenoate, acrylic and methacrylic acid, diallyl phthalate, or mixtures thereof.
These polyester blends with unsaturated mono-mers should contain about 20 to about 60 percent by weight and preferably 30 to 50 perc~nt by weight of the monomers based on the weight of the polyester. A'small amount of an inhibitor such as tertiary butyl catechol or hydroqui-none may be added to this mixture.
The final blend is a cross-linkable polyester composition which is useful to make laminates, castings or coatings.
Laminates can be made by mixing into the cross--linkable composition, free radical-forming catalysts in known amounts and ad~ing this mixture to a suitable fibrous reinforcement such as carbon fibers, fibrous glass or lnor-ganic fibers.
Examples of these catalysts are benzoyl per-~5 oxide, tertiary butyl peroxide and methylethyl ketoneperoxide. It is frequently of value to add accelerators such as cobalt naphthenate or dimethyl aniline.
28,327A-F - -5-., . . -~ 9~3~9 -~ -6-The polyester resin is roll~d, sprayed or impregnated into the fibrous reinforcement s~ch as fibrous glass and cured in a manner well-known in the art. When fibrous glass is used, it can be in any form such as chopped strands, filaments, gl~ss ribbon~, glass yarns or reinforcing mats.
The follo~ing exa~ples illustrate the inven-tion.
Example 1 The laboratory cooks were carried out in a 2-liter resin flask, equipped with a mechanical stirrer, a stainless steel N2 sparge tube, a stainless steel thermowell, and a steam heated (100C) partial condenser, followed by a trap, followed by a water cooled condenser.
The reaction heat source was two 275 watt infrared lamps and the whole resin flask was kept in a hot air oven.
The resin flask was charged with 800 ~rams (3.05 moles) of commèrcial dibromoneopentyl glycol, 170 grams (1.73 moles) of maleic anhydride, 110 grams (0.74 mole) of phthalic a~hydride and 80 yrams ~4.44 moles) of water.
The reactor was sparged with N2 (1190 cc/min) to remove air from the system prior to ~he start of the reaction and to aid in the removal of water after the reaction was started. [For comparative purposes, the cook time is considered to be that part of the cycle from the time the reaction temperature reached 125C
until the reaction was terminated.
28,327A-F -6-..
9~
The temperature controller was set at 135C
and the reaction started. The reaction reached 125C
in about 45 minutes and 135C in 55 minutes. The reac-tion temperature was maintained at 135C until the acid number reached 29. ~The normal end acid number is 30+2.) The cook time was 22 hours.
The crude alkyl was poured into a polytetra-fluoroethylene coated pan and allowed to cool.
Samples were made up for testing by dissolv-ing 75 grams of alkyd in 25 grams of styrene, contain-ing 0.02 gram of toluhydroquinone. The styrenated resin had the following properties: ~
Gardner Color 8.7 SPI Gel Time 5.1 min.
SPI Peak Time 6.9 min.
SPI Peak Exotherm 188C
.~
To a sample of this resin was added 1 weight percent epi-chlorohydrin to bleach the color. The bleached sample had the following properties:
Gardner Color 3.9 SPI Gel Time 6.1 min.
SPI Peak Time 8.1 min.
SPI Peak Exotherm 213C
28,327A-F -7-. .
, . ~
38~
Example 2 The above procedure W2S repeated except that 2.1 grams (0.011 mole) of p-TSA was added to the reactor along with the charge. The reaction reguired 5.0 hours to reach an acid nu.~er OI 30. Samples of styrenated resin were-made up as in Example 1 and the following results were o~tained:
Without With EPichlorohvdrin Epichlorohydrin 10 Gardner Color 2.4 2.4 SPI Gell Time 1.6 min........... 6.6 min.
SPI Cure Time 2.7 min. 8.8 min.
SPI Peak Exotherm 133C 209C
, ? .: / ~T '-' . . . ..
Some of these adverse reactions caused by the presence of sulfuric, or sulfonic acids, include premature gelation of the styrenated and unstyrenated resins and the loss of glycol from the cook due to the formation of vola-tile ethers. It has been shown that as little as 50 ppm of sulfuric acid will catalyze the formation of ethers from aliphatic diols at polyester reaction temperatures.
The present invention is a process for prepar-ing unsaturated polyesters by reacting an unsaturated dicarboxylic acid with a polyol composed at least in part with dibromoneopentyl glycol wherein the catalyst employed is an aryl sulfonic acid and followi~g completion of the reaction there is added a su~`ficient amount of an acid #CaVenger to neutralize s~id sulfonic acid.
An unsaturated polyest2r is a condensation polymer produced by condensing approximately equimolar proportions of at least one dicarboxylic acid, ~t least a portion of which contains ethylenic unsaturation, with at le2st one pGlyol, which for purposes of this inven-tion, must be made up at least in part of di~romoneopen-tyl glycol. Examples of such unsaturated acids include maleic, fumaric and itaconic acids. Th~ ~emainder, if 28,327A F ~
9~389 _3_ any, of the dicarboxyllc acids are usually either satu-rated nonTal aliphatics, such as adipic acid, succinic acid, or aromatic diacids, such as phthalic acid or iso-phthalic acid. The tPrm dicarboxylic acid, as used herein, S is intended to e~brace the anhydride as well.
The unsaturated acid provides the unsaturation needed for curing the resin. Therefore, the actual ratio of unsaturated acid to saturated acid will be dictated by the deg,ee of cross-linking desired in the cured product.
That degree of cross-linking may be predetermined by sim-ple preliminary experiments as is standard in the poly-ester art.
The polyol to be used is dibromoneopentyl gly-col. Other no~halogenated glycols may ~e used in small amounts without affecting the inventive concept. However, when using aryl sulfonic acids as the esterification cata-lysts, those nonhalogenated glycols form ethers and other undesirable by-products.~ The preserlt invention appears to be singularly well adapted or use with dibromoneopen-tyl glycol which must form the substantial majority ofthe polyol.
The acid scaveng~r to be use~ in the process is any compound that will neutralize -t~ acid catalyst through formation of a salt, ester, amine salt or by other means. Typical of such scavengers are the oxirane compounds, such as epichlorohydrin, the diglycidyl ether of a polyol as, for example, a diglycidyl ether of an aliphatic glycol having an epoxy equivalent weight of 175-205, and other epoxy compounds; oxetane compoun~s 28,327A-F -3-9~38~
such as bis-2,2-(dibromonethyl)oxetane; amines such as diethanolamine or triethanolamine; soluble salts of weak acids such as sodium acetate or hypophosphorous acid.
The esterification catalyst is an aryl sul-fonic acid. Typical of those acids are benzene sulfonicacid and p-toluene sulfonic acid. The amount of catalyst can vary between about 0.OS and 3 percent by weight of the reactants. Preferably, the amount is between 0.1 and 0.4 weight percent.
The polyester is made in generally conventional manner except as otherwise described herein. The acid and dibromoneopentyl glycol are introduced into a suitable esterification reaction vessel equipped with means for removing water of esterification suitably as it is ormed in the reaction. T~e reactants are blanketed with an inert atmospher~, preferably nitrogen gas, then agitated and heated to effect the reaction for a desired period of time. The reaction temperature can range from about 100C to 200C, preferably from 135C to 155C. The exact reaction time will depend on the resin ormulation, the amount of catalyst, the reaction temperature and pressure and the inert gas sparge rate.
The degree of reaction is conveniently deter-mined by measuring the acid number or by measuring the amount of water liberated in the reaction. The reaction is discontinued when the product has a desired acid num-ber, e.g., an acid number of 40 or below. After the reaction has been carried to the desired degree of com-pletion, the acid scavenger is added.
28,327A-F -4-~` , .
~ 9~8~
The resin is then recovered and blended with an ethyleni~all~- unsaturated monomer copolymerizable with the unsaturated polyester polymers to form a blend wherein the weight ratio of polyester to monomer is in the range 5 from about 4:1 to about 1;2. Such ethylenically unsatu-rated monomers are well-known and include styrene, chloro-styrene, vinyl toluene, divinylbenzene, dicyclopentadiene alkenoate, acrylic and methacrylic acid, diallyl phthalate, or mixtures thereof.
These polyester blends with unsaturated mono-mers should contain about 20 to about 60 percent by weight and preferably 30 to 50 perc~nt by weight of the monomers based on the weight of the polyester. A'small amount of an inhibitor such as tertiary butyl catechol or hydroqui-none may be added to this mixture.
The final blend is a cross-linkable polyester composition which is useful to make laminates, castings or coatings.
Laminates can be made by mixing into the cross--linkable composition, free radical-forming catalysts in known amounts and ad~ing this mixture to a suitable fibrous reinforcement such as carbon fibers, fibrous glass or lnor-ganic fibers.
Examples of these catalysts are benzoyl per-~5 oxide, tertiary butyl peroxide and methylethyl ketoneperoxide. It is frequently of value to add accelerators such as cobalt naphthenate or dimethyl aniline.
28,327A-F - -5-., . . -~ 9~3~9 -~ -6-The polyester resin is roll~d, sprayed or impregnated into the fibrous reinforcement s~ch as fibrous glass and cured in a manner well-known in the art. When fibrous glass is used, it can be in any form such as chopped strands, filaments, gl~ss ribbon~, glass yarns or reinforcing mats.
The follo~ing exa~ples illustrate the inven-tion.
Example 1 The laboratory cooks were carried out in a 2-liter resin flask, equipped with a mechanical stirrer, a stainless steel N2 sparge tube, a stainless steel thermowell, and a steam heated (100C) partial condenser, followed by a trap, followed by a water cooled condenser.
The reaction heat source was two 275 watt infrared lamps and the whole resin flask was kept in a hot air oven.
The resin flask was charged with 800 ~rams (3.05 moles) of commèrcial dibromoneopentyl glycol, 170 grams (1.73 moles) of maleic anhydride, 110 grams (0.74 mole) of phthalic a~hydride and 80 yrams ~4.44 moles) of water.
The reactor was sparged with N2 (1190 cc/min) to remove air from the system prior to ~he start of the reaction and to aid in the removal of water after the reaction was started. [For comparative purposes, the cook time is considered to be that part of the cycle from the time the reaction temperature reached 125C
until the reaction was terminated.
28,327A-F -6-..
9~
The temperature controller was set at 135C
and the reaction started. The reaction reached 125C
in about 45 minutes and 135C in 55 minutes. The reac-tion temperature was maintained at 135C until the acid number reached 29. ~The normal end acid number is 30+2.) The cook time was 22 hours.
The crude alkyl was poured into a polytetra-fluoroethylene coated pan and allowed to cool.
Samples were made up for testing by dissolv-ing 75 grams of alkyd in 25 grams of styrene, contain-ing 0.02 gram of toluhydroquinone. The styrenated resin had the following properties: ~
Gardner Color 8.7 SPI Gel Time 5.1 min.
SPI Peak Time 6.9 min.
SPI Peak Exotherm 188C
.~
To a sample of this resin was added 1 weight percent epi-chlorohydrin to bleach the color. The bleached sample had the following properties:
Gardner Color 3.9 SPI Gel Time 6.1 min.
SPI Peak Time 8.1 min.
SPI Peak Exotherm 213C
28,327A-F -7-. .
, . ~
38~
Example 2 The above procedure W2S repeated except that 2.1 grams (0.011 mole) of p-TSA was added to the reactor along with the charge. The reaction reguired 5.0 hours to reach an acid nu.~er OI 30. Samples of styrenated resin were-made up as in Example 1 and the following results were o~tained:
Without With EPichlorohvdrin Epichlorohydrin 10 Gardner Color 2.4 2.4 SPI Gell Time 1.6 min........... 6.6 min.
SPI Cure Time 2.7 min. 8.8 min.
SPI Peak Exotherm 133C 209C
, ? .: / ~T '-' . . . ..
Claims (13)
1. A process for preparing unsaturated poly-esters by reacting an unsaturated dicarboxylic acid with a polyol composed at least in part with dibromoneopentyl glycol wherein the catalyst employed is an aryl sulfonic acid and following completion of the reaction there is added a sufficient amount of an acid scavenger to neutra-lize said sulfonic acid.
2. The process of Claim l wherein said acid scavenger is an oxirane compound.
3. The process of Claim 2 wherein said oxi-rane compound is a glycidyl ether.
4. The process of Claim 3 wherein said gly-cidyl ether is a diglycidyl ether of a polyol.
5. The process of Claim 2 wherein said oxi-rane compound is epichlorohydrin.
6. The process of Claim 1 wherein the reac-tion is carried out at a temperature of from 100°C to 200°C.
7. The process of Claim 1 wherein said aryl sulfonic acid is p-toluene sulfonic acid.
28,327A-F -9-
28,327A-F -9-
8. The process of Claim 7 wherein said sul-fonic acid is present in an amount of from 0.05 to 3 per-cent by weight of the reactants.
9. The process of Claim l wherein said acid scavenger is an amine.
10. The process of Claim 9 wherein said amine is diethanolamine.
11. The process of Claim 1 wherein the reac-tion mixture contains a small amount of water or alkylene glycol.
12. A composition for making polyesters when reacted with a polycarboxylic acid, said composition com-prising a solid solution of catalytic amounts of up to 1 weight percent of an aryl sulfonic acid in dibromoneopen-tyl glycol.
13. The composition of Claim 12 wherein the aryl sulfonic acid and any residual hydrogen bromide is neutralized with an acid scavenger.
28,327A-F -10-
28,327A-F -10-
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US9925979A | 1979-12-03 | 1979-12-03 | |
US99,259 | 1979-12-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1149989A true CA1149989A (en) | 1983-07-12 |
Family
ID=22273981
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000365960A Expired CA1149989A (en) | 1979-12-03 | 1980-12-02 | Unsaturated polyesters prepared from a dicarboxylic acid and dibromoneopentyl glycol |
Country Status (2)
Country | Link |
---|---|
JP (1) | JPS5698231A (en) |
CA (1) | CA1149989A (en) |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3826806A (en) * | 1972-06-06 | 1974-07-30 | Union Carbide Corp | Flame retardant polyesters from brominated diols |
JPS5238598B2 (en) * | 1973-07-24 | 1977-09-29 | ||
DE2648969C2 (en) * | 1976-10-28 | 1986-05-07 | Dynamit Nobel Ag, 5210 Troisdorf | Copolymers based on pentabromobenzyl acrylate and tetrabromo xylylene diacrylate or the corresponding methacrylates and their use as flame retardants |
GB1572940A (en) * | 1977-07-09 | 1980-08-06 | Freeman Chemical Corp | Unsaturated polyester resin |
-
1980
- 1980-12-02 CA CA000365960A patent/CA1149989A/en not_active Expired
- 1980-12-03 JP JP16971180A patent/JPS5698231A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS5698231A (en) | 1981-08-07 |
JPH0217570B2 (en) | 1990-04-20 |
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