CA1055638A - Dry, moldable and stable unsaturated polyester resin paste - Google Patents
Dry, moldable and stable unsaturated polyester resin pasteInfo
- Publication number
- CA1055638A CA1055638A CA237,380A CA237380A CA1055638A CA 1055638 A CA1055638 A CA 1055638A CA 237380 A CA237380 A CA 237380A CA 1055638 A CA1055638 A CA 1055638A
- Authority
- CA
- Canada
- Prior art keywords
- polyester resin
- unsaturated polyester
- gel
- temperature
- resin
- 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
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J3/00—Processes of treating or compounding macromolecular substances
- C08J3/12—Powdering or granulating
- C08J3/124—Treatment for improving the free-flowing characteristics
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
- C08L67/06—Unsaturated polyesters
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2367/06—Unsaturated polyesters
Abstract
ABSTRACT OF THE DISCLOSURE
There is provided an improved process for preparing an unsaturated polyester resin in the form of a dry moldable, transparent and non-sticky paste having a shelf life of up to six months, which comprises mechanically breaking up an unsatu-rated polyester gel containing an initiator effective at a temperature of at least 80°C. into finely divided gel particles thereby to disrupt the polymerization process of the gel, adding to said finely divided gel an amount of up to 50 parts per hundred of an unpolymerized unsaturated polyester resin containing an oxide or hydroxide of a metal of Group II and an initiator effective at a temperature of at least 80°C, and after mixing allowing said mixture to stand so as to mature at a temperature of from 35 to 80°C. for a period of from 2 to 4 days.
There is provided an improved process for preparing an unsaturated polyester resin in the form of a dry moldable, transparent and non-sticky paste having a shelf life of up to six months, which comprises mechanically breaking up an unsatu-rated polyester gel containing an initiator effective at a temperature of at least 80°C. into finely divided gel particles thereby to disrupt the polymerization process of the gel, adding to said finely divided gel an amount of up to 50 parts per hundred of an unpolymerized unsaturated polyester resin containing an oxide or hydroxide of a metal of Group II and an initiator effective at a temperature of at least 80°C, and after mixing allowing said mixture to stand so as to mature at a temperature of from 35 to 80°C. for a period of from 2 to 4 days.
Description
l~SS~i3~ `
The present invention relates to a process for pre-paring unsaturated polyester resin in the form of a mouldable paste which is transparent, non-sticky and which has a shelf-life of up to about 6 months. More particularly the improved process of the present invention is particularly suited to provide an unsaturated polyester resin for the moulding of transparent or coloured objects such as buttons or other ornamentations.
PRIOR ART
Unsaturated polyester resins in gel form are well known in the art. Such gels are in the unpolymerized state or in a partially polymerized state and can be molded at tempera-tures of from 100 to 150C under pressure within a few minutes whereby cross-linking polymerization occurs to produce a hard finished article.
It is also known that transparent unsaturated poly-ester resins in the partially polymerized state whether filler are incorporated or not are sticky or tacky when handled, they have a relatively short shelf-life, about 4 to 6 weeks, and 3 20 they are highly sensitive to temperature variations. They also have a high shrinkage coefficient resulting in breakage of the molded article having a non-uniform section. Further, such products can only be used in compression molding since injection, transfermolding, extrusion and similar shaping techniques are inapplicable. Some of these disadvantages have ~ -been overcome by incorporation of filler or reinforcement fillers such as fiber glass, but of course when this is done a non-transparent product can only be obtained.
As can be readily appreciated by those skilled in the 30 art it would be advantageous for ornemental industries such as the button industry to have available an unsaturated polyester ;
5., ~ S S 63 ~
resin in the form of a mouldable paste which is transparent, non-sticky and which has a relatively long shelf-life and which could provide various consistent coloured patterns by the use of separately coloured pastes.
TH~ INVENTION
In accordance with the present invention, there is now provided an improved process whereby an unsaturated poly-ester resin which is transparent, non-sticky and which has a shelf-life of from about 5 to about ~ months is obtained.
Broadly, the improved process of the present invention comprises d;srupt;ng the polymerization processus of an unsaturated polyester gel at the stage B by mechanically breaking the gel ~nto small gel particles, adding a further amount of unsatured polyes'ter resin and, after thorough mixing, the compositlon is allowed to mature whereby a mouldable paste is obtained, the paste being transparent, non-sticky and is surprisingly stable for periods of up to about 6 months.
More specifically, the improved process of the present invention comprises preparing an unsaturated polyester ~` 20 resin gel contain;ng an initiator effective at a temperature of at least 80C, mechanically break;ng up said gel into fine particles thereby to disrupt the polymerization process of the gel, mixing the particles thus obtained with less than 50 parts per hundred of the same unsaturated polyester resin as used in preparing the starting gel and containing an oxide or hydroxide of a metal of Group II and an initiator effective a~ a tempera-ture of at least 80C, and allowing the mixture thus obta;ned to mature at a temperature of from 35 to ~0C for a period of from 2 to 4 days. The unsaturated polyester resin paste thus obtained can then be formed into sheets by passing through a roll-mill or in the form of extruded rods for future use in .
.,, , ~ ,,,.,, ~. .
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lOS5638 compression, transfer or injection moulding.
The preparation of the unsaturated polyester resin gel is known in the art and can be obtained by any of three different methods. One method involves the addition of an ionic polymerization catalyst to a stage A unsaturated poly-ester resin whereby gellification is obtained. Another method comprises the addition of polyisocyanate to a stage A unsatu-rated polyester resin. Finally gellification is obtained by incorporation of organic quaternary ammonium compounds and mercaptan into the unsaturated polyester resin.
Gelling is carried out at a temperature varying between room temperature and 40C. and the time requlred will vary between a few minutes to a few hours depending on the system used, react~vity of the resin and temperature used, as is well known to those skilled in the art. The gelling is carried out in such a way that no more the 25~ of the polymer-ization takes place.
It is important that prior to the gelling that an initiator be incorporated into the resin to induce complete cross-linking in the partially polymerized unsaturated poly-ester resin paste obtained by the present invention upon appli-cation of heat and pressure.
Preferred results are obtained when the initiator is selected from those which are effective at temperatures above 80C. As an example of suitable initiators there may be mentioned benzoyl peroxide, t-butyl per~enzoate, dicumyl peroxide, 2,5-dimethyl-2,5-(t-butylperoxy)hexane, di-t-butyl-diperphthalate, 2,5-dimethyl-2,5 dihydroperoxyde hexane, bis- -(t-butylperoxy~diisopropylbenzene~ di~t~butylperoxy~3,3,5-trimethylcyclohexane or azo initiators for example 2-t butyl-azocyanobutane, l-t-butylazo-l-cyanocyclohexane.
. ~: , , ., . ............ . . . . . , . . . : , ~ ....... .. . . .
.. : . - .. ~ , . , .~ ~ : , .. .. .
: 1~55638 When a coloured resin is desired, colouring agents or pigments are incorporated in the starting unsaturated polyester - resin, but caution must be exercised to select those which will not effect the gelling of the resin or il;s shelf~ e. For example it is known that chromophthalic pigments ~ill acceler-ate gelling and then decrease the stability of the gel whereas carbon black will tend to completely inhibit gelling.
When a transparent gel is desired fillers having a refractive index approximating that of the resins are prefer-able used. The use fillers is somewhat restricted to colloidalsilica and certain types of micronized asbestos, but because of their strong trixotropic effects, the amount should be reskr~cted to less than 2%. On the other hand dehydrated potato starch having a particle size of from 10 to 40 microns does not effect the transparency of the polyester resin and may be used in amounts of up to 30%.
Since the final polyester resin will be molded under heat in a metallic mold, it is recommended to incorporate a mold releasing agent such as an alkyl phosphate Por example under the trademark ZELEC~ or metallic stearates such as zinc stearate or calcium stearate ~n concentration oF from 1~5 to
The present invention relates to a process for pre-paring unsaturated polyester resin in the form of a mouldable paste which is transparent, non-sticky and which has a shelf-life of up to about 6 months. More particularly the improved process of the present invention is particularly suited to provide an unsaturated polyester resin for the moulding of transparent or coloured objects such as buttons or other ornamentations.
PRIOR ART
Unsaturated polyester resins in gel form are well known in the art. Such gels are in the unpolymerized state or in a partially polymerized state and can be molded at tempera-tures of from 100 to 150C under pressure within a few minutes whereby cross-linking polymerization occurs to produce a hard finished article.
It is also known that transparent unsaturated poly-ester resins in the partially polymerized state whether filler are incorporated or not are sticky or tacky when handled, they have a relatively short shelf-life, about 4 to 6 weeks, and 3 20 they are highly sensitive to temperature variations. They also have a high shrinkage coefficient resulting in breakage of the molded article having a non-uniform section. Further, such products can only be used in compression molding since injection, transfermolding, extrusion and similar shaping techniques are inapplicable. Some of these disadvantages have ~ -been overcome by incorporation of filler or reinforcement fillers such as fiber glass, but of course when this is done a non-transparent product can only be obtained.
As can be readily appreciated by those skilled in the 30 art it would be advantageous for ornemental industries such as the button industry to have available an unsaturated polyester ;
5., ~ S S 63 ~
resin in the form of a mouldable paste which is transparent, non-sticky and which has a relatively long shelf-life and which could provide various consistent coloured patterns by the use of separately coloured pastes.
TH~ INVENTION
In accordance with the present invention, there is now provided an improved process whereby an unsaturated poly-ester resin which is transparent, non-sticky and which has a shelf-life of from about 5 to about ~ months is obtained.
Broadly, the improved process of the present invention comprises d;srupt;ng the polymerization processus of an unsaturated polyester gel at the stage B by mechanically breaking the gel ~nto small gel particles, adding a further amount of unsatured polyes'ter resin and, after thorough mixing, the compositlon is allowed to mature whereby a mouldable paste is obtained, the paste being transparent, non-sticky and is surprisingly stable for periods of up to about 6 months.
More specifically, the improved process of the present invention comprises preparing an unsaturated polyester ~` 20 resin gel contain;ng an initiator effective at a temperature of at least 80C, mechanically break;ng up said gel into fine particles thereby to disrupt the polymerization process of the gel, mixing the particles thus obtained with less than 50 parts per hundred of the same unsaturated polyester resin as used in preparing the starting gel and containing an oxide or hydroxide of a metal of Group II and an initiator effective a~ a tempera-ture of at least 80C, and allowing the mixture thus obta;ned to mature at a temperature of from 35 to ~0C for a period of from 2 to 4 days. The unsaturated polyester resin paste thus obtained can then be formed into sheets by passing through a roll-mill or in the form of extruded rods for future use in .
.,, , ~ ,,,.,, ~. .
, ~
lOS5638 compression, transfer or injection moulding.
The preparation of the unsaturated polyester resin gel is known in the art and can be obtained by any of three different methods. One method involves the addition of an ionic polymerization catalyst to a stage A unsaturated poly-ester resin whereby gellification is obtained. Another method comprises the addition of polyisocyanate to a stage A unsatu-rated polyester resin. Finally gellification is obtained by incorporation of organic quaternary ammonium compounds and mercaptan into the unsaturated polyester resin.
Gelling is carried out at a temperature varying between room temperature and 40C. and the time requlred will vary between a few minutes to a few hours depending on the system used, react~vity of the resin and temperature used, as is well known to those skilled in the art. The gelling is carried out in such a way that no more the 25~ of the polymer-ization takes place.
It is important that prior to the gelling that an initiator be incorporated into the resin to induce complete cross-linking in the partially polymerized unsaturated poly-ester resin paste obtained by the present invention upon appli-cation of heat and pressure.
Preferred results are obtained when the initiator is selected from those which are effective at temperatures above 80C. As an example of suitable initiators there may be mentioned benzoyl peroxide, t-butyl per~enzoate, dicumyl peroxide, 2,5-dimethyl-2,5-(t-butylperoxy)hexane, di-t-butyl-diperphthalate, 2,5-dimethyl-2,5 dihydroperoxyde hexane, bis- -(t-butylperoxy~diisopropylbenzene~ di~t~butylperoxy~3,3,5-trimethylcyclohexane or azo initiators for example 2-t butyl-azocyanobutane, l-t-butylazo-l-cyanocyclohexane.
. ~: , , ., . ............ . . . . . , . . . : , ~ ....... .. . . .
.. : . - .. ~ , . , .~ ~ : , .. .. .
: 1~55638 When a coloured resin is desired, colouring agents or pigments are incorporated in the starting unsaturated polyester - resin, but caution must be exercised to select those which will not effect the gelling of the resin or il;s shelf~ e. For example it is known that chromophthalic pigments ~ill acceler-ate gelling and then decrease the stability of the gel whereas carbon black will tend to completely inhibit gelling.
When a transparent gel is desired fillers having a refractive index approximating that of the resins are prefer-able used. The use fillers is somewhat restricted to colloidalsilica and certain types of micronized asbestos, but because of their strong trixotropic effects, the amount should be reskr~cted to less than 2%. On the other hand dehydrated potato starch having a particle size of from 10 to 40 microns does not effect the transparency of the polyester resin and may be used in amounts of up to 30%.
Since the final polyester resin will be molded under heat in a metallic mold, it is recommended to incorporate a mold releasing agent such as an alkyl phosphate Por example under the trademark ZELEC~ or metallic stearates such as zinc stearate or calcium stearate ~n concentration oF from 1~5 to
2.0%. These can be incorporated into the polyester resin before the gelling step.
After initial gelling has taken place, that is, that a stage B unsaturated polyester resin has 6een obtained, the gel is then finely divided so as to disrupt or arrest the polymerization process of the gel. This is done 6y passing the gel through any apparatus which will cause the gel mass to be finely divided. As an example of such an apparatus there may be mentioned a grinder somewhat resembling a meat grinder where the openings through which the gel will be forced will vary .
1~55~38 between 1 to 3 millimeters, with a diameter of 1 mm being pre-ferred. The finely divided mass of gel thus obtained cannot be defined in terms of particle size, since the mass is in gel form, other than to say that it is finely divided as opposed to the original gel and in order to give an idea of what the fine particles look like, the mass obtained would resemble whatever would be obtained when passing solid gelatine through a meat grinder.
The thus extruded material has the consistency of a paste, is very sticky but is very stable due to the fact that the growth of the polymeric chain has been interrupted and due to the action of the oxygen of the air which stabilizes the free radicals.
To this paste, which is difficult to manipulate becaus~ it is sticky, there is added in a mixer a further amount of unsaturated polyester resin, (stage A~ less than 50%
but prefera61y from 10 to 25% by weight of the stage B resin.
The added unsaturated polyester resin has incorporated therein from 2 to 10% by weight of stage A resin of an oxide or hydroxide of a metal of the Group TI, along with an inhibitor and an initiator effectiye at a temperature above 80C. Also if desired there may also be added some fillers.
The oxide or hydroxide of a metal of Group II is added to reduce stickiness and as an example of such oxides there may be mentioned magnesium oxide, calcium oxide or magnesium hydroxide. The initiator is the same as the one added in the preparation of the stage B resin. There is also incorporated from 0.05 to 0~1% by weight of stage A resin of an inhibitor~ The "inhibitor" as employed in this invention is such an agent or mixture thereof which acts to inhibit free radical polymerization of said resin and monomer in course of gelation, and is selected from:
_ 5 ~ , 1~S5~38 (a) phenols such as hydroquinone, para-tertiary-butylcatechol, pyrogallol, trin;trophenol, 4-ethylcatechol, 3-phenylcatechol,
After initial gelling has taken place, that is, that a stage B unsaturated polyester resin has 6een obtained, the gel is then finely divided so as to disrupt or arrest the polymerization process of the gel. This is done 6y passing the gel through any apparatus which will cause the gel mass to be finely divided. As an example of such an apparatus there may be mentioned a grinder somewhat resembling a meat grinder where the openings through which the gel will be forced will vary .
1~55~38 between 1 to 3 millimeters, with a diameter of 1 mm being pre-ferred. The finely divided mass of gel thus obtained cannot be defined in terms of particle size, since the mass is in gel form, other than to say that it is finely divided as opposed to the original gel and in order to give an idea of what the fine particles look like, the mass obtained would resemble whatever would be obtained when passing solid gelatine through a meat grinder.
The thus extruded material has the consistency of a paste, is very sticky but is very stable due to the fact that the growth of the polymeric chain has been interrupted and due to the action of the oxygen of the air which stabilizes the free radicals.
To this paste, which is difficult to manipulate becaus~ it is sticky, there is added in a mixer a further amount of unsaturated polyester resin, (stage A~ less than 50%
but prefera61y from 10 to 25% by weight of the stage B resin.
The added unsaturated polyester resin has incorporated therein from 2 to 10% by weight of stage A resin of an oxide or hydroxide of a metal of the Group TI, along with an inhibitor and an initiator effectiye at a temperature above 80C. Also if desired there may also be added some fillers.
The oxide or hydroxide of a metal of Group II is added to reduce stickiness and as an example of such oxides there may be mentioned magnesium oxide, calcium oxide or magnesium hydroxide. The initiator is the same as the one added in the preparation of the stage B resin. There is also incorporated from 0.05 to 0~1% by weight of stage A resin of an inhibitor~ The "inhibitor" as employed in this invention is such an agent or mixture thereof which acts to inhibit free radical polymerization of said resin and monomer in course of gelation, and is selected from:
_ 5 ~ , 1~S5~38 (a) phenols such as hydroquinone, para-tertiary-butylcatechol, pyrogallol, trin;trophenol, 4-ethylcatechol, 3-phenylcatechol,
3-isobutylcatechol, etc., (b) quinones such as quinone, tetra-chloro-p-quinone, toluquinone, quinhydrone, etc., (c) aromatic amines such as N,N'-di-beta-naphthyl-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine, p-hydroquinone-diphenylamine, p-methyl-p-sulphonamide phenylamine, etc., (d~ amine salts such as tributylamine hydrochloride, etc., (e) ascorbic acid, (f) trinitrobenzene.
- 10 After thorough mixing at room temperature the final paste is then al1Owed to mature For a few days after which it is dry and easy to handle. The paste is then extruded into rods which are cut into small discs of 3 to 4 mm in thickness and stored for future use. Subsequently, these discs can be placed in the cavities of a metallic mold heated to 125-135C
under a pressure of 200-300 psi for two minutes to provide buttons.
When a coloured pattern is desired sheet of clifferent thicknesses are formed and rolled together to form a rod having a large dlameter wherein the various colours are evenly dis-persed to provide a coloured pattern on subsequent cutting into discs of 3 to 4 mm. depending on the shape of the mold.
The term unsaturated polyester resin as employed in this invention is the kind of unsaturated polyester resin that is formed by the esterification of polybasic acids including an alpha,beta-olefinically unsaturated dibasic acid with mono-and/or polyvalent alcohols comprising mainly divalent alcohols.
Typical saturated polybasic acids are the dibasic acids including phthalic acid, terephthalic acid, adipic acid, sebacic acid and the like. Typical unsaturated dibasic acids are maleic acid, fumaric acid, citraconic acid, chloromaleic ~IL05S638 acid and the like. Examples of divalent alcoho1s are ethylene glycol, diethylene glycol, polyethylene glycols, propylene glycol, mixed ethylenepropylene glycols, l,6-hexanediol, 1,3-butylene glycol, 2,3-dimethylpropane-1,3-diol and the like.
The resin then is dissolved in a monomer having an unsaturated double bond which is copolymerizable with alpha, beta-unsaturated double bonds of the polyester resin. In this instance the monomer is usually added with a polymerization - inhibiting agent or mixture thereof.
Typical unsaturated monomers copolymerizable with the unsaturated polyester resins are styrene, acrylonitrile, ethyl-vlnylbenzene, isopropenyl toluene, vinyl benzoate, methyl acrylate, methyl methacrylate, acrolein, dimethylstyrene and the like.
The unsaturated polyester resin at this point is referred to as a stage A unsaturated polyester resin by those skilled in the art. ; `
To exemplify, a typical unsaturated polyester resin is obtained in the following manner; anhydrous maleic acid, anhydrous phthalic acid, ethylene glycol, and propylene glycol in amounts corresponding to a respective mole ratio of 0.5:0.5:0.55:0.55 are reacted at 180C. until the acid value of the mixture reaches 50, and unsaturated polyester resin thus formed (100 parts) is then dissolved in 50 parts of styrene monomer to which 0.05 part of hydroquinone has been added as an inhibitor.
After partial polymerization of the stage A unsatu-rated polyester resin there is obtained a gel which is also ; referred to in the art as a stage B unsaturated polyester resin.
As an example of suitable unsaturated polyester ~ 7 : . , ., , . . : . '. . . ' . : , . . , .: ' : .' .
1~)5563~3 resins which can be used as starting material there may be mentioned products such as those sold on the market under the trademarks POLYLITE 31000 (Reichold Chemical Co.), PALATAL~
P-6 and P-70 (BASF~ of LEGUVAL~ W-21 (Bayer Co.).
The present invention will be more fully understood by referring to the following examples which are given tn illustrate the invention rather than to limit its scope.
EXAMPLE I
100 parts of POLYLITE~ 31000 (a liquid unsaturated alkyl resin dissolved in styrene and manufactured by Reichold Chemicals, Inc.), 0.1 part of 1% cobalt octoate, 0.2 part of dodecylmercaptan, 1.0 part of PERCADOX~ 29B75, 0.5 park of ZELEC~ EN (a mixture of alkyl phosphates used as a mold release agent and manufactured by E.I. DuPont de Nemours & Co.) and 2.0 parts of mother of pearl are mixed for a few minutes and then 0.1 part of methyl ethyl ketone peroxide is added. The mixture thus obtained is poured in a rectangular container placed on a shaking table to eliminate the air incorporated in the mixture.
After resting for 45 minutes the polyester resin has gelled and the gel is removed, cut in strips as passed through i a grinder having orifices of at 1 mm.
To 100 parts of the paste thus obtained there is added 15 parts of POLYLITE~ 31000, 0.5 part of magnesium oxide, 0.05 part of 2,6-di-t-butyl-p-cresol, 0.15 part of PERCADOX~
29B75, 0.10 part of ZELEC~ EN, 1 part of CAB-O-SIL~ M-5 (a colloidal silica manufactured by Godfrey L. Cabot, Inc.) and ~, ~als5638 0.30 part of mother of pearl, and mixing is carried out for about 20 minutes in a Z type mixer.
The composition is then wrapped in polyethylene sheets and stored for about 3 days after which the paste is dry, transparent non-sticky and has a shelf-life of about 6 months. The composition is then extruded in rods which are cut into discs of 3-4 mm in thickness. The individuals discs are then placed in a button mold heated to 125-135C for 2 minutes under a pressure of 200 psi to form button.
EXAMPLE~
The following ingredients are mixed for a few minutes:
parts POLYL ITE~ 31000 100 Cobalt octoate 1% 0.1 Cobalt acetylacetonate 1% 1.0 i Dibutylthiourea 0.25 PERCADOX~ 29B75 1.0 ZELEC~ UN Q.5 Colouring paste 0.2 Potato starch (20 - 40 microns~ 30.
After mixing there is then added 0.1 part oF cyclohexanone peroxide. The mixture is allowed to rest for 2 to 3 hours in a ~lat container to yield a transparent and coloured gel. The gel is then passed through a grinder and lQO parts of the finely divided gel thus obtained are placed in a sigma mixer and the following are added:
g ~ S S 6 3 ~
- parts POLYLITE~ 31000 20 Magnesium hydroxide 1.0 PERCADOX~ 29B75 0.2 ZELEC UN 0.1 Colouring paste 0.04 Potato starch 6.
After thorough mixing the composition is stored in a container for 3 to 4 days after which time the composition is dry, non-sticky, transparent and has a shelf-life of 6 months. The composition can then be used as in Example I.
EXAMPLE III
The following ingredients are mixed for a Few minutes:
Ingredients parts POLYLITE~ 31000 100 Cobalt octoate 1% 0.6 Dicumyl peroxide 1.0 Titanium dioxide paste 1.0 2,5-di-t-butyl-p-benzoquinone 0.45 Potato starch 30.
~ELEC~ UN 0.5 After mixing there is added 1 part of methyl ethyl ketone peroxide. The mixture is allowed to rest for 2 to 3 hours in a flat container to yield a transparent white gel. The gel is then passed through a grinder and 100 parts of the finely divided gel thus obtained are placed in a sigma mixer and the following are added:
.
'' ~
' 1~55~3~
parts POLYLITE~ 31000 15 Titanium dioxide 0.15 Calcium oxide 0.5 2,6-di-t-butyl-p-cresol 0.05 After thorough mixing the composition is stored in a container for 3 to 4 days after which time the composition is dry, non-sticky, transparent and has a shelf-life of 6 months.
- It is noted in the examples that the unsaturated polyester resin which is added to the unsaturated polyester resin gel is the same, but a different unsaturated polyester resin could be also added instead of the same. The important thing is that the unsaturated polyester resin which is to be ~ added must not be in gel form, but in the unpolymerized form.
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- 10 After thorough mixing at room temperature the final paste is then al1Owed to mature For a few days after which it is dry and easy to handle. The paste is then extruded into rods which are cut into small discs of 3 to 4 mm in thickness and stored for future use. Subsequently, these discs can be placed in the cavities of a metallic mold heated to 125-135C
under a pressure of 200-300 psi for two minutes to provide buttons.
When a coloured pattern is desired sheet of clifferent thicknesses are formed and rolled together to form a rod having a large dlameter wherein the various colours are evenly dis-persed to provide a coloured pattern on subsequent cutting into discs of 3 to 4 mm. depending on the shape of the mold.
The term unsaturated polyester resin as employed in this invention is the kind of unsaturated polyester resin that is formed by the esterification of polybasic acids including an alpha,beta-olefinically unsaturated dibasic acid with mono-and/or polyvalent alcohols comprising mainly divalent alcohols.
Typical saturated polybasic acids are the dibasic acids including phthalic acid, terephthalic acid, adipic acid, sebacic acid and the like. Typical unsaturated dibasic acids are maleic acid, fumaric acid, citraconic acid, chloromaleic ~IL05S638 acid and the like. Examples of divalent alcoho1s are ethylene glycol, diethylene glycol, polyethylene glycols, propylene glycol, mixed ethylenepropylene glycols, l,6-hexanediol, 1,3-butylene glycol, 2,3-dimethylpropane-1,3-diol and the like.
The resin then is dissolved in a monomer having an unsaturated double bond which is copolymerizable with alpha, beta-unsaturated double bonds of the polyester resin. In this instance the monomer is usually added with a polymerization - inhibiting agent or mixture thereof.
Typical unsaturated monomers copolymerizable with the unsaturated polyester resins are styrene, acrylonitrile, ethyl-vlnylbenzene, isopropenyl toluene, vinyl benzoate, methyl acrylate, methyl methacrylate, acrolein, dimethylstyrene and the like.
The unsaturated polyester resin at this point is referred to as a stage A unsaturated polyester resin by those skilled in the art. ; `
To exemplify, a typical unsaturated polyester resin is obtained in the following manner; anhydrous maleic acid, anhydrous phthalic acid, ethylene glycol, and propylene glycol in amounts corresponding to a respective mole ratio of 0.5:0.5:0.55:0.55 are reacted at 180C. until the acid value of the mixture reaches 50, and unsaturated polyester resin thus formed (100 parts) is then dissolved in 50 parts of styrene monomer to which 0.05 part of hydroquinone has been added as an inhibitor.
After partial polymerization of the stage A unsatu-rated polyester resin there is obtained a gel which is also ; referred to in the art as a stage B unsaturated polyester resin.
As an example of suitable unsaturated polyester ~ 7 : . , ., , . . : . '. . . ' . : , . . , .: ' : .' .
1~)5563~3 resins which can be used as starting material there may be mentioned products such as those sold on the market under the trademarks POLYLITE 31000 (Reichold Chemical Co.), PALATAL~
P-6 and P-70 (BASF~ of LEGUVAL~ W-21 (Bayer Co.).
The present invention will be more fully understood by referring to the following examples which are given tn illustrate the invention rather than to limit its scope.
EXAMPLE I
100 parts of POLYLITE~ 31000 (a liquid unsaturated alkyl resin dissolved in styrene and manufactured by Reichold Chemicals, Inc.), 0.1 part of 1% cobalt octoate, 0.2 part of dodecylmercaptan, 1.0 part of PERCADOX~ 29B75, 0.5 park of ZELEC~ EN (a mixture of alkyl phosphates used as a mold release agent and manufactured by E.I. DuPont de Nemours & Co.) and 2.0 parts of mother of pearl are mixed for a few minutes and then 0.1 part of methyl ethyl ketone peroxide is added. The mixture thus obtained is poured in a rectangular container placed on a shaking table to eliminate the air incorporated in the mixture.
After resting for 45 minutes the polyester resin has gelled and the gel is removed, cut in strips as passed through i a grinder having orifices of at 1 mm.
To 100 parts of the paste thus obtained there is added 15 parts of POLYLITE~ 31000, 0.5 part of magnesium oxide, 0.05 part of 2,6-di-t-butyl-p-cresol, 0.15 part of PERCADOX~
29B75, 0.10 part of ZELEC~ EN, 1 part of CAB-O-SIL~ M-5 (a colloidal silica manufactured by Godfrey L. Cabot, Inc.) and ~, ~als5638 0.30 part of mother of pearl, and mixing is carried out for about 20 minutes in a Z type mixer.
The composition is then wrapped in polyethylene sheets and stored for about 3 days after which the paste is dry, transparent non-sticky and has a shelf-life of about 6 months. The composition is then extruded in rods which are cut into discs of 3-4 mm in thickness. The individuals discs are then placed in a button mold heated to 125-135C for 2 minutes under a pressure of 200 psi to form button.
EXAMPLE~
The following ingredients are mixed for a few minutes:
parts POLYL ITE~ 31000 100 Cobalt octoate 1% 0.1 Cobalt acetylacetonate 1% 1.0 i Dibutylthiourea 0.25 PERCADOX~ 29B75 1.0 ZELEC~ UN Q.5 Colouring paste 0.2 Potato starch (20 - 40 microns~ 30.
After mixing there is then added 0.1 part oF cyclohexanone peroxide. The mixture is allowed to rest for 2 to 3 hours in a ~lat container to yield a transparent and coloured gel. The gel is then passed through a grinder and lQO parts of the finely divided gel thus obtained are placed in a sigma mixer and the following are added:
g ~ S S 6 3 ~
- parts POLYLITE~ 31000 20 Magnesium hydroxide 1.0 PERCADOX~ 29B75 0.2 ZELEC UN 0.1 Colouring paste 0.04 Potato starch 6.
After thorough mixing the composition is stored in a container for 3 to 4 days after which time the composition is dry, non-sticky, transparent and has a shelf-life of 6 months. The composition can then be used as in Example I.
EXAMPLE III
The following ingredients are mixed for a Few minutes:
Ingredients parts POLYLITE~ 31000 100 Cobalt octoate 1% 0.6 Dicumyl peroxide 1.0 Titanium dioxide paste 1.0 2,5-di-t-butyl-p-benzoquinone 0.45 Potato starch 30.
~ELEC~ UN 0.5 After mixing there is added 1 part of methyl ethyl ketone peroxide. The mixture is allowed to rest for 2 to 3 hours in a flat container to yield a transparent white gel. The gel is then passed through a grinder and 100 parts of the finely divided gel thus obtained are placed in a sigma mixer and the following are added:
.
'' ~
' 1~55~3~
parts POLYLITE~ 31000 15 Titanium dioxide 0.15 Calcium oxide 0.5 2,6-di-t-butyl-p-cresol 0.05 After thorough mixing the composition is stored in a container for 3 to 4 days after which time the composition is dry, non-sticky, transparent and has a shelf-life of 6 months.
- It is noted in the examples that the unsaturated polyester resin which is added to the unsaturated polyester resin gel is the same, but a different unsaturated polyester resin could be also added instead of the same. The important thing is that the unsaturated polyester resin which is to be ~ added must not be in gel form, but in the unpolymerized form.
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Claims (4)
1. An improved process for preparing an unsaturated polyester resin in the form of a dry moldable, transparent and non-sticky paste having a shelf-life of up to six months, which comprises mechanically breaking up an unsaturated polyester gel containing an initiator effective at a temperature of at least 80°C. into finely divided gel particles thereby to disrupt the polymerization process of the gel, adding to said finely divided gel an amount of up to 50 parts per hundred of an unpolymerized unsaturated polyester resin containing an oxide or hydroxide of a metal of Group IIA in an amount of from 2 to 10% by weight of the unpolymerized unsaturated polyester resin and from 0.05 to 0.1% by weight of said resin of an initiator effective at a temperature of at least 80°C, and after mixing allowing said mixture to stand so as to mature at a temperature of from 35 to 40°C. for a period of from 2 to 4 days.
2. The process of Claim 1, wherein the amount of unpolymerized polyester resin is from 10 to 25 parts per hundred.
3. The process of Claim 1, wherein the metal oxide is magnesium oxide.
4. The process of Claim 1, wherein the metal oxide is calcium oxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA237,380A CA1055638A (en) | 1975-10-06 | 1975-10-06 | Dry, moldable and stable unsaturated polyester resin paste |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA237,380A CA1055638A (en) | 1975-10-06 | 1975-10-06 | Dry, moldable and stable unsaturated polyester resin paste |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1055638A true CA1055638A (en) | 1979-05-29 |
Family
ID=4104236
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA237,380A Expired CA1055638A (en) | 1975-10-06 | 1975-10-06 | Dry, moldable and stable unsaturated polyester resin paste |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1055638A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0045621A2 (en) * | 1980-08-06 | 1982-02-10 | Coloroll Limited | Plastics starch composition |
-
1975
- 1975-10-06 CA CA237,380A patent/CA1055638A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0045621A2 (en) * | 1980-08-06 | 1982-02-10 | Coloroll Limited | Plastics starch composition |
| EP0045621A3 (en) * | 1980-08-06 | 1982-02-17 | Coloroll Limited | Plastics based composition |
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