Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
ORGANIC NITROGEN-CONTAINING POLYMERIZATION COCATALYST
Document Type and Number:
WIPO Patent Application WO/1990/012824
Kind Code:
A1
Abstract:
Accelerator compositions for the curing of unsaturated maleic, vinylic, allylic and epoxy-type polyesters, are disclosed. The accelerator compositions comprise a complex of a salt of a metal selected from lithium, vanadium, copper, nickel, magnesium, iron and cobalt, and a nitrogen-containing compound capable of forming a complex with these metal salts and being selected from ammonia, ammonium salts, amines, amides, heterocyclic nitrogen compounds and their adducts with anhydrides and epoxides. Also disclosed are a curable composition comprising resin and the accelerator composition of the invention and a curing process carried out in the presence of an accelerator composition of the invention.

Inventors:
GIOVANDO GUALTIERO (IT)
Application Number:
PCT/EP1990/000727
Publication Date:
November 01, 1990
Filing Date:
April 26, 1990
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
AKZO NV (NL)
SAINT PETER SRL (IT)
International Classes:
C08F299/04; C08G59/68; C08K5/00; (IPC1-7): C08F4/06; C08F299/04; C08K5/00
Foreign References:
FR2014908A11970-04-24
GB1192166A1970-05-20
EP0043484A11982-01-13
US3796689A1974-03-12
DE1216546B1966-05-12
US3565822A1971-02-23
US3091936A1963-06-04
Attorney, Agent or Firm:
Schalkwijk, Pieter (Velperweg 76 Postbus 9300, SB Arnhem, NL)
Download PDF:
Claims:
What is claimed is:
1. An accelerator composition which comprises a complex of a salt of at least one metal selected from the group consisting of lithium, copper and magnesium, and an amine selected from the group consisting of 3aminomethyl3,5dimethylcyclohexylamine, diaminodicyclohexylmethane, isophoronediamine, dimethylbenzylamine, trimethylamine, triethylamine, dimethylamine, diethylamine, secondary and tertiary amines having electronrepellant subsitutents and adducts of these amines with anhydrides and epoxides.
2. An accelerator composition which comprises a complex of a salt of at least one metal selected from the group consisting of lithium, vanadium, copper, nickel, magnesium, iron and cobalt, and a nitrogencontaining compound selected from the group consisting of ammonia, ammonium salts, amides and heterocyclic nitrogen compounds, with the proviso that when said metal salt is a lithium salt, said ammonium salt is ammonium acetate.
3. An accelerator composition as claimed in any one of claims 12 wherein said epoxide adduct is formed with an epoxide selected from the group consisting of butylglycidylether, ethylhexylglycidylether, Ci3_i5alkylglycidylether, phenylglycidylether, cresylglycidylether, cycloaliphatic epoxides and ptertiarybutylphenylglycidylether.
4. An accelerator composition as claimed in any one of claims 12 wherein said anhydride adduct is formed with an anhydride selected from the group consisting of the anhydrides of methylhexahydrophthalic, methyltetrahydrophthalic, methylendomethylenetetrahydrophthalic, maleic and dodecylsuccinic.
5. An accelerator composition as claimed in any one of claims 14 which further comprises a sufficient amount of an oxygenated organic compound which includes at least one functional group selected from the group consisting of aldehyde, ketone, ether, ester, or alcohol to enhance the accelerative effect of said nitrogencontaining accelerator composition.
6. An accelerator composition in accordance with claim 5 wherein said oxygenated compound is selected from the group consisting of keto and aldoesters, ethers or alcohols, 1,3diketones, and dialdehydes, 1,2diketones, mono and diesters and polyalcohols.
7. An accelerator composition in accordance with claim 6 wherein said oxygenated compound is selected from the group consisting of ethylacetoacetate, monoand diesters of ketoglutaric acid, esters of pyruvic acid, glucose, fructose, acetylacetone, benzoylacetone, dibenzoylmethane, diethylmalonate, succinates, diacetyl, glyoxal, diethyleneglycol , benzylglycol and ascorbic palmitate.
8. A process for the curing of a resin selected from the group consisting of unsaturated maleic, allylic, vinylic and epoxytype resins, said process comprising the step of curing said resin in the presence of a curing agent composition comprising at least one accelerator composition as claimed in any one of claims 17 and 050 weight percent of at least one ethylenically unsaturated reactive monomer.
9. A process as claimed in claim 8 wherein said accelerator composition is present in an amount corresponding to a metal content of from 0.1 to 200 on the basis of the weight of said resin.
10. A process as claimed in any one of claims 89 wherein said ethylenically unsaturated monomer is selected from the group consisting of styrene and styrene derivatives such as αmethylstyrene, indene, divinyl benzene, stilbene, dibenzalacetone, propenyl benzene and isopropenyl benzene; trially! cyanurate, triallyl isocyanurate and mixtures thereof.
11. A process as claimed in any one of claims 810 wherein said curing agent composition further comprises from 0.02 to 5.0 weight percent of a peroxide initiator based on the weight of said resin.
12. A curable composition which comprises a resin or prepolymer selected from the group consisting of unsaturated maleic, allylic, vinylic and epoxytype polyesters, 050 weight percent of an ethylenically unsaturated reactive monomer, 05.0 weight percent of a peroxide initiator and an effective amount of an accelerator as claimed in any one of claims 17, all weight percentages being based on the weight of said resin.
Description:
Organic Nitrogen-Containing Polymerization Cocatalyst

The present invention relates generally to accelerators for the curing of unsaturated polyester resins, often in the presence of peroxide initiators. More particularly, the accelerators are complexes of nitrogen-containing compounds and one or more metal salts.

Aliphatic heterocyclic amines are known as stabilizers for ketone peroxide solutions from Netherlands patent application 6713010. These ketone peroxides are suitable for use as cross-linking agents for unsaturated polyester resin compositions.

In addition, Canadian patent 672,487 discloses the use of peroxides and a hardening agent in the curing of unsaturated polyester resins. Among the disclosed hardening agents are amine accelerators such as N,N-dimethyl aniline, N,N-dimethyl toluidine, p-dimethylamine benzophenone, p.p'-tetramethyldiamino diphenyl ethane, p.p'-tetramethyldiamino dipehnylkenton and tri-(p-aminophenyl)methane.

European patent application 0 160 621 discloses a hardening composition for epoxy resins which comprises a peroxide free radical initiator and an accelerator. The accelerator may be, among others an aliphatic amine with at least 2 primary amino groups, a keti ine of such an amine, a polyisocyanate, an aldimine, a tertiary amine and a quaternary ammonium salt.

Japanese patent application J6-1000227 discloses the use of isophoronediamine as an accelerator for the curing of a glycidyl compound in the presence of a vinyl-containing liquid compound. Japanese patent application J5-5145311 discloses a thermosetting resin comprising dicyclohexylamine, an unsaturated polyester resin other than epoxy, benzoyl peroxide, styrene and manganese naphthanate. Japanese patent application J5-1034985 discloses the curing of an unsaturated polyester resin using a peroxide, a cobalt naphthenate and

an α-alkyl-β-ketoimine. British patent specification 2,120,653 discloses the curing of unsaturated polyester resins with tertiary amine accelerators obtained by the reaction of a p-substituted aminobenzene with a glycidyl compound.

U.S. patent 4,309,511 discloses the curing of an unsaturated polyester resin comonomer composition using cobalt, copper and a heterocyclic amine cure promoter- The preferred heterocyclic amine is a bicyclic heterocyclic amine and especially triethylene diamine.

U.S. patent 3,804,799 discloses accelerators or promoters for polyester resin curing which comprise a coordination complex of triethylene diamine or a homolog thereof, with one or more metal salts selected from cobalt, zinc and nickel salts. The triethylene diamine compound is preferably employed as a solution in a glycol or other suitable solvent such as styrene.

East German patent DL-121524 contains a very broad disclosure of numerous possible accelerators for unsaturated polyesters, which accelerators contain nitrogenous electron donors and chelate forming groups. For example, among the numerous listed compounds are ammonia, primary, secondary and tertiary aliphatic, cycloaliphatic or aromatic amines, piperidine, piperazine, pyridine, indole and amines incorporated ' into unsaturated polyesters. The patent itself only exemplifies a very limited class of amines which are always used in combination with cobalt salts and optionally acetoacetonate.

German patent DT-2905660 discloses the initiation of polymerization of unsaturated polyesters and acrylates at low temperature by a system containing a halogen compound, an amine and a metal compound. Numerous amines are mentioned alone with metals such as iron, cobalt, nickel, manganese, vanadium, mercury and copper.

U.S. patent 3,886,113 discloses the use of metal complexes of triethylene diamine compounds with salts of cobalt and manganese as accelerators in the free-radical initiated curing and cross-linking of unsaturated polyester resins.

German patent application DS 2641 108 discloses a high gloss epoxy resin acrylate polymer powder coating composition which contains a lithium salt and a quaternary ammonium compound as accelerators. U.S. patent 3,663,599 discloses the use of lithium salts in combination with a quaternary ammonium compound to promote the polymerization of vinyl monomers.

In the field of curing accelerators/catalysts there exist very specialized requirements for each and every curing system. Thus, there remains a need for the development of new combinations of curing accelerators which exhibit specific advantageous properties and provide the ability to more completely control the parameters of the cure procedure. The present invention has for one of its objects to meet these demands.

SUMMARY

For the curing of unsaturated maleic, vinylic, allylic and epoxide- type polyesters, use as accelerators is made of salts of a metal chosen from among lithium, vanadium, copper, nickel, magnesium, iron, and cobalt, in combination with one or more compounds of, organo-nitrogenated type, that are capable of forming complexes with such salts. The invention includes curable compositions containing these accelerators and curing processes carried out in the presence of these accelerators.

DESCRIPTION

The present invention refers generally to processes for the curing of unsaturated maleic, allylic, vinylic, and epoxide-type polyesters by means of radical or ionic-radical catalysis, and provides accelerators/promoters for the curing process. It has been established that certain metal salts that can form complexes with organic nitrogen compounds, are able to substantially accelerate the process of curing of the abovementioned resins. Particularly the salts of a metal selected from among copper, vanadium, lithium, nickel, iron, magnesium and cobalt, can be utilized for the curing of the above-mentioned resins or prepolymers, in the presence of a nitrogenated compound chosen from among ammonia, ammoniacal, aminic and amidic compounds, and heterocyclic nitrogen compounds.

The metal salt, which may be a halide, acetate, nitrate, lactate or hexanoate, -- preferably a chloride or acetate -- can be made to interact with the nitrogenated compound to form a coordination compound. Hence the scope of the invention includes an accelerator compound comprising a complex between a nitrogenated compound and one or more salts of the abovementioned metals.

Preferably the complex between the metal salt and the nitrogenated compound is added to the resin in an amount corresponding to a metal content ranging from 0.1 to 200 ppm referred to the weight of the resin. For the individual metals the preferred amounts are as follows:

Cu, from 0.1 to 10 ppm,

Co, from 1 to 20 ppm,

Li, from 1 to 100 ppm, Fe, from 5 to 150 ppm,

Mg, from 3 to 200 ppm, and

Ni and V, from 0.1 to 200 ppm. Amounts in excess of those indicated above, do not further contribute to the activity.

Within the scope of the present invention, the preferred compounds for the formation of the complexes are primary cycloaliphatic amines such as isophorone diamine (S-aminomethyl-S.δ.δ-trimethylcyclohexylamine) and diaminodicyclohexylmethane, secondary aliphatic amines, in particular dimethylamine and diethylamine, tertiary aromatic, aliphatic and cycloaliphatic amines such as dimethylbenzylamine, trimethylamine, and triethylamine. It is implied that substitution products and adducts of the abovespecified amines can also be used. Particularly advantageous are adducts of primary cycloaliphatic amines with anhydrides and epoxides.

As nitrogenated products capable of forming accelerator complexes according to the invention, one should further consider ammonia, ammonium salts, and heterocyclic nitrogenated bases. Ammonium salts soluble in the resin are particularly effective in combination with copper, lithium, magnesium and iron. Most preferred among these materials is ammonium acetate.

By way of example, the adducts with the nitrogen-containing compounds can be obtained by means of addition reactions with an anhydride chosen from among maleic, hexahydrophthalic, tetrahydrophthalic, methyltetrahydrophthalic, methylnadic (methyl endomethylenetetrahydrophthalic), succinic, dodecylsuccinic, pyro ellitic, and chlorendic. Useful epoxide compounds for the production of an adduct with the nitrogen-containing compound, include alkyl (C3..18 . diglycidyl ethers, polypropylenoxydiglycidyl ethers, polytetramethylenoxydiglycidyl ethers, butylglycidylether, 2-ethyleneglycidylether, alkylglycidylether, phenylglycidylether, o- cresylglycidylether, p-tertiary butylphenyl glycidylether, glyceroldiglycidyl ether, hexanedioldiglycidyl ether, glycyldiglycidyl ethers, neopentenediglycidyl ether, Bisphenol-A diglycidyl ether, Bisphenol-F diglycidyl ether, and cycloaliphatic epoxides such as vinylcyclohexenediepoxide and cycloaliphatic epoxides of formula:

o Formu1a ! in which R is chosen among alkylene, oxygen, -O-R3-O, -O-CO-R3-CO-O; R3 being alkylene; R is hydrogen or methyl; R2 is hydrogen or =0.

In a preferred embodiment, the present invention refers to promoters of the amine type.

The amine-type promoter is a compound belonging to the group that consists of: cyclohexylaliphatic amines, secondary and tertiary C1-C3 alkylamines, and addition compounds of the said amines.

The aminic promoters present the advantages of being only slightly toxic, enabling distillation of styrene during the stage of crosslinking, and of other reactive substances, and allowing a good efficiency of polymerization. Further advantages are achieved regarding the quality of the products that are produced from the curable polymeric compositions. They include an only slight shrinkage, high mechanical resistance, a transparent or almost colourless cross!inked mass, and the possibility of easily varying and controlling the parameters during the crosslinking (time, temperature etc.), thus readily permitting the embedding of delicate inserts into the material to be cross!inked.

In the most preferred embodiment of the invention the crosslink promoter comprises a cyclohexylaliphatic amine being a cyclohexylamine mono-, di- or trisubstituted in the cyclohexyl ring by radicals selected from the group that consists of C1-C3 alkyls, amino-Cι-C3 alkyls and cyclohexylamino-Cι-C3 alkyls, more specifically isophoronediamine (3-aminomethyl-3,5,5-trimethylcyclohexylamine) and diaminodicyclohexylmethane.

In another preferred embodiment of the invention the crosslink promoter comprises a secondary or tertiary amine with substituents of the electron-repulsor type, in particular lower alkyls: e.g., trimethylamine, triethylamine, diethylamine and dimethylamine.

In yet other preferred embodiments of the invention, the promoters are addition products of the above-stated amines with epoxides, anhydrides, chlorinated compounds, aldehydes and ketones. Such adducts are realized in order to diminish the toxicity of the amines and to improve their solubility and compatibility with resins, thereby achieving a better product quality.

Good results have been obtained by reacting the isophorone diamine or diaminodicyclohexylmethane with an epoxide like, for example, butylglycidylether, ethylhexylglyci-dylether, C12-C15 alkylglycidylether, phenylglycidylether, cresylglycidylether or paratertiarybutylphenylglycidylether, and cycloaliphatic epoxides.

Good results were also obtained by reacting the isophoronediamine or diaminodicyclohexylmethane with an anhydride like, for example, maleic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecylsuccinic anhydride or methyltetrahydrophthalic anhydride.

In a second aspect, the present invention relates to a curable composition which comprises a resin selected from unsaturated maleic, allylic, vinylic and epoxy-type polyester resins and an accelerator selected from those detailed herein. Such curable compositions preferably also comprise at least one peroxide curing agent. Standard peroxide curing agents used in the curing of unsaturated resins such as benzoyl peroxide, peroxycarbonates and ketone peroxides, among others may be employed. The peroxide initiator generally comprises from 0.02 to 5.0 weight percent of the composition and more preferably, 0.1 to 1.0 weight percent, based on the weight of the resin.

Another aspect of the curable composition of the present invention comprises a curable mixture of a resin or prepoly er chosen from among the group of unsaturated polyester resins, maleic, allylic, vinylic and epoxy-type resins, and at least one ethylenically unsaturated reactive monomer in the presence of an accelerator. Typical ethylenically unsaturated reactive monomers include styrene and styrene derivatives such as α-methylstyrene, indene, divinyl benzene, stilbene, dibenzalacetone, propenyl benzene and isopropenyl benzene; trially! cyanurate, trially! isocyanurate and mixtures thereof. The ethylenically unsaturated reactive monomer may comprise from 0-50 weight percent, based on the weight of the resin.

The curable composition may also contain other, optional ingredients including conventional curing accelerators, oxygenated compounds and standard resin additives in addition to the foregoing listed materials.

The curable composition generally contains the amount of metal complex as specified earlier herein. The nitrogen-containing material itself is generally employed in an amount of 0.01 to 20% by weight, and more preferably, 0.1 to 10% by weight, based on the weight of the resin.

In a third aspect, the present invention relates to a process for curing an unsaturated maleic, allylic, vinylic or epoxy-type resin in the presence of at least one accelerator of the type described herein. In the curing procedure, the curable composition is cured at room temperature or higher.

In the curing process of the present invention, one begins with the resin composition. To this there may optionally be added an ethylenically unsaturated reactive monomer. The accelerator composition may be added in several different manners. For example, the accelerator composition, may be pre-mixed to form the metal salt complex prior to it being added to the resin composition. Another

possibility is to add the individual components of the accelerator composition to the resin and form the metal complex j_n situ, which of these methods is preferred will depend on the specific curing process being carried out.

Other additives, such as the peroxide initiator, or other accelerator enhancing materials may be added directly to the resin without first mixing them with the accelerator composition. However, in some cases it may be desirable to premix the accelerator enhancing materials with one or more of the accelerator components prior to introduction to the resin composition. The relative amounts of the materials used in the curing process are the same as those specified earlier with respect to the accelerator and curable compositions of the present invention.

Salts of copper, vanadium, lithium and magnesium can furthermore be utilized as accelerators in combination with a first compound -- a nitrogenated one -- and an oxygenated compound. In this case, too, it is considered that the metal salt forms a complex with the two compounds. The nitrogenated compounds to be taken in consideration here, are the same as those previously described.

The oxygenated organic compound is a compound which includes an aldehyde, ketone, ether, ester or alcohol group therein. The oxygenated compound must be capable of forming a complex with the metal salts and the nitrogen-containing compound.

In particular, the following can be employed as the oxygenated compound:

— keto- and aldo-esters and ethers or alcohols, in particular ethylacetoacetate, mono- and diesters of ketoglutaric acid, pyruvates, sugars such as glucose and fructose;

-- 1,3-diketones and aldehydes, in particular acetylacetone, benzoylacetone, dibenzoylmethane;

— mono- and diesters more in particular diethylmalonate, succinates, and ascorbic palmitate,

-- 1,2-diketones, in particular diacetyl and glyoxal; and

-- certain polyalcohols and other alcohols such as diethyleneglycol , benzyl alcohol and alcohols of the fatty series. The oxygenated compounds are generally employed in an amount of 0.002 to 3.0 weight percent, based on the weight of the resin. More particularly, with respect to specific materials, diethyleneglycol is generally employed in an amount of 0.01 to 0.2 weight percent and ascorbic pal itate is employed in an amount of 0.02 to 0.1 weight percent based on the weight of the resin.

The invention will be further illustrated by the examples appended hereto.

Examples 1-5

Polymerization tests relating to the DSM NX 530 polyester resin

(100 g) were effectuated with the use of accelerators consisting of complexes of salts of copper, nickel, lithium and magnesium with isophorone diamine, diaminodicyclohexylmethane and ammonium acetate. A peroxidic initiator was employed consisting of 75% methylethylketone peroxide in dibutyl phthalate, added to the resin in 2% weight ratio. The results pertaining to the polymerization tests are reported in Table I.

Example 6

An accelerator was prepared by mixing in 1:1 ratio a 10% solution of cobalt acetate with a 25% solution of ammonium acetate. The thus obtained accelerator was added in 0.25% weight ratio to 100 g of DSM NX 530 resin. The results of this polymerization test are reported in Table II.

Examples 7 and 8 In example 7 an accelerator was prepared in analogy to the accelerator obtained according to example 6, but with the cobalt acetate being replaced by a 10% solution of iron acetate. In example 8 the accelerator was a mixture of 1 part of 25% ammonium acetate solution and 1 part, by weight, of a mixture of the acetates of cobalt, copper

and lithium. The results of this polymerization are reported in Table II.

Example 9 A polymerization test was carried out on the E200 CHEM-PLAST epoxy resin, using 100 g of resin and 15 g of curing agent which was isophorone diamine. The accelerator was a complex obtained from copper chloride with isophorone diamine, and was added to the resin in 0.5% quantity. A polymerization yield of 90% was attained in 25 minutes, the temperature at the exothermal peak being 167°C. A comparison test under the same conditions but in the absence of accelerator, gave 90% polymerization yield in 60 minutes, the temperature at the exothermic peak being 125°C.

Example 10: "Beta" accelerator

This accelerator was obtained by mixing 7 g of isophoronediamine with

6 g of cresyldiglycidylether, 12 g ascorbic palmitate, and 7 g of ethyleneglycol and heating at 80°C for 1 hour. Separately, a mixture of 11 g ethylacetoacetate and 14 g methylnadic anhydride was prepared, heating to 80°C for 1 hour. The thus obtained products were mixed with the further addition of 0.15 g copper sulphate and 14.85 g diethyleneglycol .

Example 11 The procedure of example 10 was repeated, with the isophoronediamine being replaced by diaminodicyclohexylmethane or ammonium acetate.

Example 12

The procedure of example 10 was repeated, with the further addition of one gram of lithium chloride dissolved in 9 g of diethyleneglycol .

Example 13

The procedure of example 10 was repeated, with the further addition of one gram of lithium chloride, and of magnesium chloride.

Examples 14-18

Polymerization tests were carried out, using the accelerators of examples 10, 12 and 13, on DSM NX 530 unsaturated polyester resin. The peroxidic initiator was 75% methylethylketone peroxide in dibutylphthalate, in amounts varying between 0.1 and 0.3 weight % referred to the weight of the resin sample which was 100 g. All tests were done in a thermostatted bath of 25°C. The results have been collected' in Table IV.

In this case again, the best results were obtained when using a quantity of initiator equal to about 1/10 of the conventional amount; the resulting samples were bright transparent yellow, very hard, and exhibited low volatilization of styrene during and after the polymerization.

These tests demonstrate that the use of mixed complexes can, in certain cases, be particularly advantageous in terms of increased activity. As the experimental tests bring out, the invention provides new accelerators that are especially active in the curing of unsaturated, maleic, allylic, vinylic and epoxy-type polyester resins. Such accelerators can be advantageously employed as they allow to vary the temperature of the exothermal peak and the times of cross-linking. These accelerators can find special application in the cross-linking of resins intended to embed delicate inserts, e.g. in the electronics and natural sciences fields.

TABLE I

Resin DSM NX 530 (100 g)

Initiator: 1:1 mixture of methylethylketone peroxide and acetylacetone peroxide

Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5

Metal ion Cu Cu Li Li Mg

0,2 ppm 7 ppm 2 ppm 50 | _pm 200 ppm

Nitrogen compound (1) (2) (1) (3) (1)

1% 1% 1% 1% 1%

Time of final gelation 10' 9' 32' 20' 30'

Time from final gelation to exothermal peak 20' 11' 27' 18' 28'

Tpe CC) 93% 98% 90% 95% 92%

Quantity of initiator 2% 2% 2% 2% 2%

(wt.%)

(1) Isophorone diamine

(2) Ammonium acetate

(3) Diaminodicyclohexylmethane

TABLE II

Resin DSM NX 530

Initiator: 1:1 mixture of methylethylketone peroxide and acetylacetone peroxide

Accelerator according to Ex. 6 according to Ex. 7 according to Ex.8

Time of final gelation 5' 15' 7"

Time from final gelation to exothermal peak 5" 17' 6'

Temperature at exothermal peak 130° 107° 122°

Yield of cross-linking after 24 hours 99% 96% 98%

Quantity of initiator 2% 2% 2%

(wt.%)

TABLE III

Resin DSM NX 530 (100 g)

Initiator: MEK Peroxide

Type of complex Quantity of complex Time from final Tpe Note

(wt.%) gelation to (°C) exothermal peak

Example 6 0.5% 12' 131 Greenish-brown polymer

Copper chloride + oi isophorone diamine (0,5%) 0.4% 13' 128 Transparent, bright yellow

2 wt.% MEK peroxide used.

TABLE IV Resin DSM NX 530

Example 16 17 18 19 20

Peroxide%, weight to resin 0.3% 0.3% 0.1% 0.3% 0.3%

Catalyst "β" (Ex. 12) 1% 2% 1%

(wt.%)

Catalyst "β" + Li

(Ex. 14) (wt.%) — — ~ 2%

Catalyst "β" - Cu

+ Li + Mg (Ex. 15) — — — 1.5%

(wt.%)

Time of final gelation 4' 2,30" 14' 16' 17 '

Time from final gelation en to exothermal peak 5' 2' 15' 11 ' 14'

Temperature at exothermal peak(°C) 121° 123° 81° 120° 95°

NOTE Light-yellow-coloured samples, transparent, very hard

- col ourl ess

- translucent

- low- toxic

Example 19

To 100 g of NX 530 polyester resin, to which 10% methylmethacrylate had been added, were further added 0.15 g of isophoronediamine and one gramme of a 1:1 mixture of methylethylketone peroxide and acetylacetone peroxide. The mixture was made to crosslink in a bath kept at 25° temperature. The time necessary to achieve final gelation turned out to be 20 minutes, while 25 minutes elapsed before reaching the temperature of the exothermal peak, which was found at 26°C. After 10 hours a crosslinking had been attained of 75% calculated with the DSC method, the product being decidedly colourless. The yield could be further increased up to 85-90% by a post-curing treatment conducted at 50-80° for 3-5 hours.

Examples 20-24 Examples 20 to 24 were conducted by the identical procedure to that in example 19, the only variables being the nature and amount of the amine. The process parameters, and the results obtained, are reported in Table 5, together with those for example 19.

Examples 25-31

In this series of examples the polymer composition submitted to cross¬ linking was made up of 100 g of Resin 52060 -- a product of Alusuisse --, 0.15 g of cycloaliphatic amine viz. isophoronediamine, and 1 g of any of the peroxides specified in Table 6. Like in the previous case, Table 6 reports for the various examples the time elapsed until final gelation, the time having passed before arriving at the temperature of an exothermal peak, that temperature itself, the temperature at which the test was conducted, and the crosslinking efficiency.

Within the scope of the invention the form of the embodiment can be varied much beyond what has been described here purely by way of examples, without transgressing the limits of the invention.

TABLE V

Example Amine species Quantity of Quantity of Time of Time for Temperature amine (g) peroxide (g) final arriving at in exothermal Note gelation exothermal peak (°C)

(min) peak (min)

19 iphorone diamine 0.15 1 20' 25' 26° Quite colourless product

20 Adduct of isophorone 00 diamine and cresyl di¬ glycidyl ether 0. 25' 31' 26°

21 Cyclohexylmethane diamine 0.15 17' 23' 28°

22 Adduct of cyclohexyl¬ methane diamine and methylnadic anhydride 0.5 23' 24' 28°

23 Dimethyl dibenzyl- diamine 0.15 15' 30' 31° Barely straw-co¬ loured product

24 Triethylamine 0.15 13' 30' 32°

TABLE VI

Example Type of peroxide Quantity of Time of final Time for arrival Temperature in Temperature of Efficiency of (AK 20) peroxide (g) gelation (h.trrin) exothermic peak exothermic peak execution of test cross-linking

(h, min) (°C) (°C) after 24 hours

25 Butanox 50 1,40' 2,30' 26° 25° 75% Methylethyl- ketone peroxide

26 Trigonox 44B 1,50' 2,30' 27° 25° 75% Acetylacetone peroxide

27 Cyclonox 11 2,30' 1,00' 88° 45° 9H IO cyclohexane peroxide

28 Lucidol CH 50 0,30' 0,25' 97 = 40° 93% Benzoyl peroxide

29 Trigonox C 0,35' 0,28' 130° 80° 98% Tertiary-butyl perbenzoate

30 Trigonox 22 B 50 0,27' 0,25' 128° 80° 98% l-bis(tertbutyl- peroxy)cyclohexane

31 Per Kadox 16 3,30' 1,30' 37° 30° 75% Bis(4-tertbutyl- cyclohexyl)peroxy- dicarbonate