阅读说明：本技术 可用于树脂固化的加速剂溶液 (Accelerator solutions useful for resin curing ) 是由 A·埃尔斯拜依 E·科罗克 于 2019-02-11 设计创作，主要内容包括：含有基于具有一个或多个S-C-N、S-C-C-N、或S-C(＝S)-S部分的有机配体的过渡金属络合物的加速剂溶液可用于加速树脂如不饱和聚酯树脂的过氧化物固化。(Accelerator solutions containing transition metal complexes based on organic ligands having one or more S-C-N, S-C-N, or S-C (═ S) -S moieties are useful for accelerating the peroxide cure of resins such as unsaturated polyester resins.)

1. An accelerator solution comprising:

a) at least one transition metal complex of at least one transition metal and at least one organic ligand, the at least one transition metal being selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt, the at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety; and

c) at least one solvent.

2. The accelerator solution of claim 1, wherein the at least one transition metal is selected from the group consisting of: fe. Cu, Zn and Ni.

3. An accelerator solution according to claim 1 or 2, wherein the at least one organic ligand comprises at least one moiety selected from:

formula (I): -X-C-C-SH, wherein X is N, NH or NH₂and-X-C-is part of an aliphatic or saturated, unsaturated or aromatic ring structure;

formula (II): -X-C (═ S) -X¹-, where X is S, SH, N or NH, X1 is NH or NH₂And the-X-C-X1-moiety is part of an aliphatic or saturated, unsaturated or aromatic ring structure; or

Formula (III): -S-C (═ S) -S-.

4. An accelerator solution according to any one of claims 1 to 3, wherein the at least one organic ligand comprises at least one moiety selected from the group consisting of: h₂N-C-C-SH, -N-C-SH, H, in which N and C are part of an aromatic ring₂N-C (═ S) -, and-NH-C (═ S) -.

5. An accelerator solution according to any one of claims 1 to 4, wherein the at least one ligand is selected from the group consisting of: mercaptopyridine, acetylthiourea, trithiocyanuric acid, rhodanine, cysteamine, 2-imino-4-thiobiuret, thiourea, and bis (carboxymethyl) trithiocarbonate and deprotonated derivatives thereof.

6. An accelerator solution according to any one of claims 1 to 5, wherein the accelerator solution is Co-free.

7. An accelerator solution according to any one of claims 1 to 6, wherein the accelerator solution additionally comprises at least one base or at least one carboxylic acid.

8. An accelerator solution according to any one of claims 1 to 7, wherein the accelerator solution additionally comprises at least one nitrogen-containing base or at least one saturated aliphatic carboxylic acid.

9. An accelerator solution according to any one of claims 1 to 8, wherein the composition additionally comprises at least one ethoxylated amine or at least one C1-C6 aliphatic carboxylic acid.

10. An accelerator solution according to any one of claims 1 to 9, wherein the complex has been prepared by combining a transition metal salt with at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety in the presence of at least one solvent.

11. An accelerator solution according to any one of claims 1 to 10, wherein the complex has been prepared by combining a transition metal salt with at least one organic ligand in the presence of at least one solvent, the at least one organic ligand comprising at least one moiety selected from:

formula (I): -X-C-SH, wherein X is N, NH or NH2, and-X-C-is part of an aliphatic or saturated, unsaturated or aromatic ring structure;

formula (II): -X-C (═ S) -X¹-, where X is S, SH, N or NH, X1 is NH or NH₂And the-X-C-X1-moiety is part of an aliphatic or saturated, unsaturated or aromatic ring structure; or

Formula (III): -S-C (═ S) -S-.

12. An accelerator solution according to any one of claims 1 to 11, wherein the at least one solvent is selected from the group consisting of: alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, aldehydes, ketones, ethers, esters, phosphates, carboxylic acids, amides, sulfoxides and N-alkylpyrrolidones, and combinations thereof.

13. An accelerator solution according to any of claims 1 to 12, wherein the at least one solvent is selected from the group consisting of aliphatic polyols.

14. An accelerator solution according to any one of claims 1 to 13, wherein the transition metal complex is selected from the group consisting of: complexes of acetylthiourea with Fe; complexes of acetylthiourea with Cu; complexes of acetylthiourea with Zn; a complex of thiocyanuric acid with Fe; complexes of thiocyanuric acid with Cu; complexes of rhodanine with Fe; complexes of rhodanine with Cu; a complex of cysteamine with Cu; a complex of 2- (butylamino) ethanethiol (butylcysteamine) with Cu; a complex of bis (carboxymethyl) trithiocarbonate with Cu; a pyrithione-Cu complex, a Zn pyrithione complex, an Fe pyrithione complex, and an iminothiobiuret-Cu complex.

15. A method of curing a curable resin, the method comprising combining the curable resin with at least one peroxide and at least one accelerator solution according to any one of claims 1 to 14.

16. The method of claim 15, wherein the at least one peroxide is selected from the group consisting of organic peroxides.

17. The method of claim 15 or 16, wherein the at least one peroxide is selected from the group consisting of: ketone peroxides, peroxyesters, diaryl peroxides, dialkyl peroxides, peroxydicarbonates, peroxycarbonates, peroxyketals, hydroperoxides, diacylperoxides, and hydrogen peroxide.

18. The method of any one of claims 15 to 17, wherein the at least one peroxide is selected from the group consisting of: ketone peroxides, peroxyesters, monoperoxydicarbonates.

19. The method of any of claims 15-18, wherein the at least one peroxide comprises methyl ethyl ketone peroxide.

20. The method of any one of claims 15-19, wherein the at least one peroxide is a liquid at 25 ℃.

21. The method of any one of claims 15 to 20, wherein the curable resin is selected from the group consisting of: alkyd resins, unsaturated polyester resins, vinyl ester resins, and (meth) acrylate resins.

22. The method of any one of claims 15 to 21, wherein the curable resin is selected from the group consisting of unsaturated polyester resins.

23. A cured resin obtained by the method of any one of claims 15 to 22.

24. A method for preparing an accelerator solution, the method comprising reacting at least one transition metal salt comprising at least one of Fe, Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt with at least one organic ligand comprising at least one S-C-N, S-C-N, or S-C (═ S) -S moiety in an organic solvent so as to form at least one transition metal complex from the at least one transition metal salt and the at least one organic ligand.

25. An accelerator solution obtained by the method of claim 24.

26. A pre-accelerated curable resin comprising at least one curable resin and at least one accelerator solution according to any one of claims 1 to 14.

27. A two-component system comprising a first component and a second component, wherein the first component comprises at least one pre-accelerated curable resin according to claim 26 and the second component comprises at least one peroxide.

28. A cured resin composition comprising a cured resin and at least one transition metal complex of at least one transition metal and at least one organic ligand, the at least one transition metal being selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt, the at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety.

Technical Field

The present invention generally relates to accelerator solutions, processes for making such accelerator solutions, processes for curing curable resins using such accelerator solutions, cured resins obtained using such accelerator solutions, pre-accelerated curable resins containing such accelerator solutions, and two-component systems in which such pre-accelerated curable resins constitute one component.

Background

Peroxides are commonly used as initiators for curing (crosslinking) various types of resins, particularly resins containing monomers and/or oligomers having ethylenically unsaturated sites, such as unsaturated polyester resins and acrylic resins. It is common practice in the art to use one or more metal-based catalysts or accelerators in combination with the peroxide to modify or control the cure characteristics of the peroxide.

Conventional methods for promoting liquid organic peroxides (e.g., methyl ethyl ketone peroxide, also known as MEKP) involve the use of transition metal catalysts (e.g., cobalt salts) that react with the peroxide via a redox mechanism. In this reaction, the co (ii) ions oxidize to co (iii) and the peroxide initiator is reduced, generating reactive RO-radicals that are effective to initiate polymerization of unsaturated polyester resins, acrylic resins, and the like. Although cobalt salts have been the most widely used catalysts for promoting peroxides such as MEKP, such catalysts have significant drawbacks such as 1) high toxicity to humans and the environment, often even in ppm amounts, leading to increasingly stringent government regulations throughout the world, 2) relatively high cost compared to catalysts based on other transition metals, and 3) their tendency to impart intense color (brown or black) to the cured resin, which limits commercial application of the final product.

These drawbacks of conventional cobalt-based catalysts have led to studies on the possibility of using other types of transition metal catalysts based on larger amounts of transition metals such as Fe, Cu, Zn and Ni, as these metals are cheaper and less toxic than Co and tend to produce cured resins of lighter color. However, these metals are inherently less reactive than cobalt, and their salts alone are not sufficient to promote MEKP and other liquid peroxides. Therefore, new accelerating systems and formulations have recently been developed in which these metals, in particular Fe and Cu, are mixed with oxygen-containing, and/or nitrogen-containing, and/or phosphorus-containing organic ligands. However, these ligands often need to be used in relatively large amounts and in combination with nitrogen-containing bases, reducing agents, stabilizers, and other components to achieve the desired reactivity, and gelling and curing rates/kinetics. Furthermore, the resulting formulations often have low long-term stability due to metal precipitation over time, which leads to reduced performance after prolonged storage.

Thus, it is desirable to develop new accelerator systems for peroxide accelerators that are Co-free, more environmentally friendly, and do not have the above-mentioned detrimental attributes while achieving the desired reactivity, gel and/or cure rate, and good shelf life.

Disclosure of Invention

It has now been found that certain organic compounds containing sulfur and nitrogen atoms or trithiocarbonate moieties can be effective promoters for transition metals such as Fe, Cu, Ni and Zn. Such organic compounds may act as ligands for the transition metal, thereby increasing the reactivity of the transition metal with respect to its ability to facilitate peroxide initiated curing of ethylenically unsaturated resin systems, such as unsaturated polyester resins, wherein polymerization of such systems may be effectively initiated even at ambient (room) temperatures. Effective organic ligands found to be useful for this purpose are those containing one or more structural subunits (moieties) characterized by having sulfur and nitrogen atoms separated by one or two carbon atoms (i.e., S-C-N and S-C-N moieties), such as mercaptopyridine, acetylthiourea, thiocyanuric acid, rhodanine, cysteamine, 2-imino-4-thiobiuret, 2- (butylamino) ethanethiol, 2-aminothiophenol, N-phenylthiourea and thiourea (where such ligands may be in deprotonated form when complexed to a transition metal), and the like. It has also been found that compounds containing at least one trithiocarbonate moiety (S-C (═ S) -S) act as potent ligands for the purposes of the present invention.

Such organic ligands can be relatively low cost and can be readily obtained from commercial sources, and also effectively activate transition metals such as Fe, Cu, Ni, and Zn (which are also relatively low cost and have lower toxicity/environmental issues, as compared to conventional Co-based accelerators), such that the metals accelerate peroxides such as methyl ethyl ketone peroxide at room temperature, resulting in the curing of ethylenically unsaturated resins such as unsaturated polyester resins with the desirably high exotherm. It has been surprisingly found that the curing kinetics exhibited by specific transition metal complexes of this type can be further fine tuned or controlled by varying the organic ligand/transition metal ratio and/or adding different amounts of inexpensive organic acids or bases. Furthermore, the organic ligands are used in relatively low amounts (typically less than 0.4 wt% relative to the weight of the curable resin) and are capable of producing cured resins having a light or colorless color, which is highly desirable in certain end use applications where the appearance of articles made from such cured resins is important.

Thus, according to certain aspects of the present invention, there is provided an accelerator solution comprising:

a) at least one transition metal complex of at least one transition metal and at least one organic ligand, the at least one transition metal being selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt, the at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety; and

b) at least one solvent.

In other aspects, a method of curing a curable resin is provided, wherein the method comprises the step of combining the curable resin with at least one peroxide and at least one such accelerator solution. The invention also relates to a cured resin obtained by such a method.

According to a further aspect, the present invention also provides a process for preparing an accelerator solution, the process comprising reacting at least one transition metal salt comprising at least one of Fe, Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt with at least one organic ligand comprising at least one S-C-N, S-C-N, or S-C (═ S) -S moiety in an organic solvent so as to form at least one transition metal complex from the at least one transition metal salt and the at least one organic ligand. A further aspect of the invention provides an accelerator solution obtained by such a method.

In other aspects of the invention, there is provided a pre-accelerated curable resin comprising at least one curable resin and at least one accelerator solution, wherein the accelerator solution comprises:

a) at least one transition metal complex of at least one transition metal and at least one organic ligand, the at least one transition metal being selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt, the at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety; and

b) at least one solvent.

In a further aspect of the invention, a two-component system is provided comprising a first component and a second component, wherein the first component comprises at least one pre-accelerated curable resin according to such a pre-accelerated curable resin and the second component comprises at least one peroxide.

Still a further aspect of the present invention relates to a cured resin composition comprising a cured resin and at least one transition metal complex of at least one transition metal and at least one organic ligand, the at least one transition metal being selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt, the at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety.

Detailed Description

Transition metal

The transition metal component of the transition metal complex may be one or more transition metals selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt. According to a specific embodiment, the one or more transition metals are selected from the group consisting of Fe, Cu, Zn and Ni, or from the group consisting of Fe, Cu and Zn, or from the group consisting of Fe and Cu. In some embodiments, copper is most preferred. The accelerator solution may be formulated to be substantially free of cobalt or completely free of cobalt. For example, the accelerator solution may comprise less than 100ppm, less than 50ppm, less than 25ppm, less than 10ppm, or less than 1ppm Co. Two or more transition metals may be present in the transition metal complex, and the accelerator solution may include two or more transition metal complexes.

The transition metal can be in any oxidation state, including higher and lower oxidation states.

The transition metal complex may be generally prepared by reacting a transition metal compound functioning as a transition metal source in the complex with an organic compound functioning as an organic ligand component source in the transition metal complex. Suitable transition metal compounds for such purposes generally include the halides, nitrates, sulfates, sulfonates, phosphates, oxides, and carboxylates of the above-mentioned transition metals. Examples of suitable halides include bromides and chlorides. Examples of suitable carboxylates include lactate, 2-ethylhexanoate, acetate, propionate, butyrate, oxalate, laurate, oleate, linoleate, palmitate, stearate, acetylacetonate, octanoate, nonanoate, heptanoate, neodecanoate, and naphthenate.

The transition metal may be present in the accelerator solution in an amount (determined as the metal) that provides (once the accelerator solution is formulated into a curable composition), for example, 0.5 to 2mmol of metal per kilogram of curable resin.

The concentration of transition metal in the resin system to be cured may be selected and adjusted as may be necessary to achieve a particular desired cure profile, but is typically from 0.1 to 5mmol of metal per kg of curable resin.

Organic ligands

Ligands useful in the transition metal complexes used according to the invention include organic compounds comprising at least one S-C-N, S-C-N, or S-C (═ S) -S (trithiocarbonate) moiety or two or more of such moieties. That is, suitable ligands may be generally characterized as compounds in which there is a) a sulfur atom separated from a nitrogen atom by one or two carbon atoms or b) a trithiocarbonate group. Without wishing to be bound by theory, it is believed that such S-C-N or S-C (═ S) -S moieties may allow the ligands in at least certain embodiments of the invention to function as bidentate ligands, in which both the sulfur atom and the nitrogen atom or both sulfur atoms are bonded to the same transition metal atom in the transition metal complex. These bonds may be covalent in nature, including coordinate covalent bonds. The sulfur and nitrogen atoms in the above moieties may be protonated (e.g., where the sulfur atom is present as part of a thiol group, or where the nitrogen atom is present as part of a primary or secondary amino group), but in certain embodiments of the invention, one or more of the sulfur and/or nitrogen atoms in the precursor compound used as the source of the organic ligand is initially protonated, but becomes deprotonated as a result of reaction with the transition metal compound used to form the transition metal complex.

According to certain aspects of the invention, the transition metal complex contains at least one organic ligand comprising at least one moiety corresponding to formula (I):

-X-C-C-SH(I)

wherein X is N, NH or NH₂and-X-C-C-is part of an aliphatic or saturated, unsaturated or aromatic ring structure.

According to other aspects, the transition metal complex contains at least one organic ligand comprising at least one moiety corresponding to formula (II):

-X-C(＝S)-X¹-(II)

wherein X is S, SH, N or NH, X¹Is NH or NH₂And said-X-C-X¹Part is part of an aliphatic or saturated, unsaturated or aromatic ring structure.

According to other aspects, the transition metal complex contains at least one organic ligand comprising at least one moiety corresponding to formula (III):

-S-C(＝S)-S(III)。

in still further embodiments of the present invention, the at least one organic ligand present in the transition metal complex comprises at least one moiety selected from the group consisting of: h₂N-C-C-SH, -N-C-SH, H, in which N and C are part of an aromatic ring₂N-C (═ S) -, -NH-C (═ S) -, and-S-C (═ S) -S-.

Preferred organic ligands suitable for use in the present invention include mercaptopyridine, acetylthiourea, trithiocyanuric acid, rhodanine, cysteamine, 2-imino-4-thiobiuret, 2- (butylamino) ethanethiol (butylcysteamine), bis (carboxymethyl) trithiocarbonate, and thiourea, and deprotonated derivatives thereof. In certain embodiments, more preferred organic ligands include 2- (butylamino) ethanethiol (butylcysteamine), acetylthiourea, bis (carboxymethyl) trithiocarbonate, rhodamine, cysteamine, or combinations thereof.

The concentration of organic ligand in the resin system to be cured may be selected and adjusted as may be required to achieve a particular desired cure profile, but is typically from 0.01 to 0.5% by weight of the curable resin.

Preferred transition metal complexes

The following transition metal complexes have been found to be particularly effective in accelerating the cure of curable resins, especially unsaturated polyester resins, using peroxides:

fe, Cu and Zn complexed with mercaptopyridine and deprotonated derivatives thereof;

fe, Cu and Zn complexed with acetylthiourea and deprotonated derivatives thereof;

cu and Fe complexed with trithiocyanuric acid and deprotonated derivatives thereof;

cu and Fe complexed with rhodanine and deprotonated derivatives thereof;

cu complexed with cysteamine and deprotonated derivatives thereof;

cu complexed with 2- (butylamino) ethanethiol (butylcysteamine or BuCysA) and deprotonated derivatives thereof;

cu complexed with bis (carboxymethyl) trithiocarbonate and deprotonated derivatives thereof;

cu complexed with 2-imino-4-thiobiuret and deprotonated derivatives thereof;

zn complexed with thiourea and deprotonated derivatives thereof;

and combinations thereof.

Solvent(s)

The accelerator solution according to the invention contains, in addition to the at least one transition metal complex, one or more solvents, which are typically organic solvents. Such solvents typically aid in solubilizing the transition metal complex and/or provide a suitable liquid medium in which the organic ligand precursor and transition metal compound are reacted to form the transition metal complex. Depending on the solvent chosen and the nature of the transition metal compound and the organic ligand precursor, the solvent may also participate in the complexation of the transition metal. That is, in addition to the organic ligands described elsewhere herein, the transition metal complex may also contain one or more solvent molecules or derivatives thereof as ligands.

The particular solvent or combination of solvents present in the accelerator solution is not believed to be particularly critical, and any of a wide variety of solvents may be used. For example, in various embodiments of the present invention, the accelerator solution comprises at least one solvent selected from the group consisting of: alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, aldehydes, ketones, ethers, esters, phosphates, phosphites, carboxylic acids, amides, sulfoxides (e.g., dimethyl sulfoxide) and N-alkylpyrrolidones (e.g., N-methyl and N-ethylpyrrolidones), and combinations thereof. In some embodiments, alcohols are preferred.

As used herein, the term "alcohol" refers to any organic compound containing one or more hydroxyl groups per molecule. In one embodiment of the invention, aliphatic alcohols are used. In another embodiment, the accelerator solution comprises at least one aliphatic polyol (i.e., an aliphatic alcohol containing two or more hydroxyl groups per molecule, such as a glycol). Examples of suitable alcohols are polyols (including glycols) such as ethylene glycol, diethylene glycol, dipropylene glycol, polyethylene glycol, glycerol, ethoxylated glycerol, pentaerythritol and ethoxylated pentaerythritol, and monoalkyl ethers thereof. Other types of suitable alcohols include, but are not limited to, isobutanol, pentanol, benzyl alcohol, and fatty alcohols.

Specific examples of suitable phosphates and phosphites include diethyl phosphate, dibutyl phosphate, tributyl phosphate, triethyl phosphate (TEP), dibutyl phosphite, and triethyl phosphate.

Examples of suitable aliphatic hydrocarbon solvents include white spirit (white spirit), Odorless Mineral Spirits (OMS), and paraffin wax.

Examples of suitable aromatic hydrocarbon solvents include cycloalkanes and mixtures of cycloalkanes and paraffins, 1, 2-dioxime, N-methylpyrrolidone, N-ethylpyrrolidone; dimethylformamide (DMF); dimethylsulfoxide (DMSO); 2,2, 4-trimethylpentanediol diisobutyrate (TxIB);

suitable esters include, but are not limited to, esters such as dibutyl maleate, dibutyl succinate, ethyl acetate, butyl acetate, mono-and diesters of ketoglutaric acid, pyruvates, esters of ascorbic acid such as ascorbyl palmitate, diethyl malonate, and succinate.

Suitable ketones include 1, 2-diketones, in particular butanedione and glyoxal.

The accelerator solution may optionally comprise water. The water content of the accelerator solution, if present, may be, for example, at least 0.01 wt% or at least 0.1 wt%. The water content is preferably not more than 50 wt.%, more preferably not more than 40 wt.%, more preferably not more than 20 wt.%, even more preferably not more than 10 wt.%, and most preferably not more than 5 wt.%, all based on the total weight of the accelerator solution.

Other Components of the Accelerator solution

The accelerator solution according to the invention may contain, in addition to the transition metal complex and the solvent, one or more further types of components. Such additional components may, for example, have the effect of further accelerating or improving the solid properties of the curable resin when mixed with the peroxide and accelerator solution. These types of components may be referred to as adjuvants, accelerators, auxiliary accelerators or other such terms.

In one embodiment, the accelerator solution may additionally comprise one or more bases, in particular one or more organic bases such as organic amines or other nitrogen-containing organic compounds. Such bases are distinct from the organic ligands present in the transition metal complex of the accelerator solution, which may in some cases be considered bases due to the presence of amine functional groups, although in one embodiment of the invention excess (unreacted) organic ligand precursor may be present in the accelerator solution and act as an adjuvant, promoter, or co-accelerator.

Suitable exemplary bases that may be present in the accelerator solution and the pre-accelerated curable resin include primary, secondary, and tertiary amines, such as triethylamine, dimethylaniline, diethylaniline, or N, N-dimethyl-p-toluidine (DMPT), polyamines, such as 1,2- (dimethylamine) ethane, secondary amines, such as diethylamine, ethoxylated amines, such as triethanolamine, dimethylaminoethanol, diethanolamine, or monoethanolamine, and aromatic amines, such as pyridine or bipyridine. The base is preferably present in the accelerator solution in an amount of 5 to 50 wt%. In the pre-accelerator curable resin, the base is preferably present in an amount of 0.5 to 10g/kg resin.

When the organic ligand is a bis (carboxymethyl) trithiocarbonate, it has been found to be particularly advantageous to use one or more bases in combination with such an organic ligand.

In other embodiments of the present invention, the accelerator solution may additionally comprise one or more carboxylic acids. Particular preference is given to saturated carboxylic acids, especially relatively short-chain saturated carboxylic acids, such as C1-C6 saturated carboxylic acids. The carboxylic acid may contain one or more carboxylic acid functional groups per molecule. Butyric acid is an example of a particularly preferred carboxylic acid additive in the accelerator solution. It has been found that the incorporation of a carboxylic acid such as butyric acid in an accelerator solution reduces the cure time and increases the observed exotherm temperature when the accelerator solution is used in combination with a peroxide to cure a curable resin such as an unsaturated polyester resin. The amount of carboxylic acid in the accelerator solution can be varied to achieve a particular cure profile that may be desired, but typical amounts can be from 1 to 10 wt% based on the weight of the accelerator solution.

According to certain embodiments of the invention, the organic ligand may contain one or more carboxylic acid groups. Bis (carboxymethyl) trithiocarbonate is an example of such an organic ligand.

Other types of promoters that may optionally be present in the accelerator solution include ammonium, alkali metal, and alkaline earth metal carboxylates, alkali metal and alkaline earth metal halide salts, and 1, 3-diketones.

Examples of suitable halide salts of alkali and alkaline earth metals include, for example, chloride and bromide salts of potassium, sodium, lithium, calcium, barium and magnesium, such as NaCl, LiCl, KCl, MgCl₂、CaCl₂And BaCl₂。

Examples of suitable 1, 3-diketones include acetylacetone, benzoylacetone, and dibenzoylmethane, as well as acetoacetamides and acetoacetates such as diethyl acetoacetamide, dimethyl acetoacetamide, dipropyl acetoacetamide, dibutyl acetoacetamide, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, and butyl acetoacetate.

Examples of suitable carboxylates of ammonium, alkali metals, and alkaline earth metals are 2-ethylhexanoates (i.e., octanoates), nonanoates, heptanoates, neodecanoates, and naphthenates. The preferred alkali metal is K. Potassium 2-ethylhexanoate is an example of a particularly suitable carboxylate. The salts themselves may be added to the accelerator solution or resin, or they may be formed in situ. For example, the alkali metal 2-ethylhexanoate salt can be prepared in situ in the accelerator solution after the alkali metal hydroxide and 2-ethylhexanoic acid are added to the accelerator solution.

In other embodiments of the present invention, the accelerator solution may additionally contain one or more reducing agents. These reducing agents include ascorbic acid (L-ascorbic acid and D-erythorbic acid), oxalic acid, mercaptans, sugars (fructose, glucose, and other sugars), aldehydes, Sodium Formaldehyde Sulfoxylate (SFS), phosphines, phosphites, sulfites, sulfides, and mixtures thereof. The reducing agent may be present in an amount typically from 0.1 to 5 wt% based on the weight of the accelerator solution.

In other embodiments of the present invention, the accelerator solution may additionally contain one or more free radical deactivators. These radical deactivators include nitroxide radical deactivators such as TEMPO, 4H-TEMPO, SG-1, and derivatives thereof. It has been found that when an accelerator solution is used in combination with a peroxide to cure a curable resin, such as an unsaturated polyester resin, the incorporation of a free radical deactivator in the accelerator solution increases the cure time without affecting the observed exotherm temperature. The free radical deactivator may be present in an amount typically from 0.01 to 1 wt% based on the weight of the accelerator solution.

Method for producing transition metal complex and accelerator solution

The accelerator solution may be prepared by simply mixing the ingredients, optionally with intermediate heating and/or mixing steps. The transition metal complex may be added to the solution as a preformed complex or may be formed in situ by combining the organic ligand and the transition metal salt with the one or more solvents, optionally followed by heating. The mixture was stirred with or without heating until the components dissolved and a homogeneous solution was obtained. The weight or molar ratio of organic ligand to transition metal salt may be varied as desired depending on the particular transition metal salt(s) and organic ligand(s) selected. In certain embodiments, for example, an excess of organic ligand relative to the transition metal salt may be used, while in other embodiments, the transition metal salt is in excess relative to the organic ligand. The pre-accelerated curable resin may be prepared in various ways, including by mixing the individual components with the curable resin and by mixing the curable resin with the accelerator solution according to the invention.

Curable resin

Suitable resins that may be cured using the accelerator solution according to the invention or that may be present in the pre-accelerated curable resin composition include, but are not limited to, alkyd resins, Unsaturated Polyester (UP) resins, vinyl ester resins, (meth) acrylate resins (sometimes referred to as acrylic resins), polyurethanes, epoxy resins, and mixtures thereof. Preferred resins include (meth) acrylate resins, UP resins and vinyl ester resins. In the context of the present application, the terms "unsaturated polyester resin" and "UP resin" refer to a combination of one or more unsaturated polyester resins and one or more ethylenically unsaturated monomer compounds, such as styrene, which are typically used to reduce the viscosity of the unsaturated polyester resin and act as a crosslinker during polymerization. Unsaturated polyester resins are condensation polymers typically formed by the reaction of a polyol (also known as a polyhydric alcohol) with saturated and/or unsaturated dibasic acids. The term "(meth) acrylate resin" refers to a combination of an acrylate and/or methacrylate resin and an ethylenically unsaturated monomeric compound. Such UP resins and acrylate resins are well known in the art and are commercially available. Curing is generally initiated by combining the accelerator solution according to the invention and the one or more initiators (peroxides) with the curable resin, or combining the one or more peroxides with the pre-accelerated curable resin.

The unsaturated polyester resins useful in the present invention comprise a reactive resin dissolved in a polymerizable monomer or mixture of monomers. These reactive resins are formed by condensing a saturated dicarboxylic acid or anhydride and an unsaturated dicarboxylic acid or anhydride with a dihydric alcohol. Examples of these polyester resins include products of reaction of saturated dicarboxylic acids or anhydrides (e.g., phthalic anhydride, isophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, tetrachlorophthalic anhydride, hexachloroendomethylenetetrahydrophthalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, or sebacic acid) and unsaturated dicarboxylic acids or anhydrides (e.g., maleic anhydride, fumaric acid, chloromaleic acid, itaconic acid, citraconic acid, or mesaconic acid) with dihydric alcohols (e.g., ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, or neopentyl glycol). A small amount of a polyhydric alcohol (e.g., glycerol, pentaerythritol, trimethylolpropane, or sorbitol) may be used in combination with the diol.

The three-dimensional structure may be produced by reacting an unsaturated polyester via an unsaturated acid component with an unsaturated monomer that is capable of reacting with the unsaturated polyester to form crosslinks. Suitable unsaturated monomers include styrene, methyl styrene, dimethyl styrene, vinyl toluene, divinyl benzene, dichlorostyrene, methyl acrylate, ethyl acrylate, methacrylate, diallyl phthalate, vinyl acetate, triallyl cyanurate, acrylonitrile, acrylamide, and mixtures thereof. The relative amounts of unsaturated polyester and unsaturated monomer in the unsaturated polyester resin composition may vary within wide ranges. The unsaturated polyester resin composition generally contains 20 to 80% by weight of monomers, and the monomer content is preferably in the range of from 30 to 70% by weight.

Vinyl ester resins include resins prepared by esterification of an epoxy resin with an unsaturated carboxylic acid such as acrylic acid and methacrylic acid, followed by dissolution of the resulting product in a reactive solvent such as styrene (typically to a concentration of 35 to 45 percent by weight).

Acrylate resins include acrylates, methacrylates, diacrylates and dimethacrylates, high functionality acrylates and methacrylates (including both monomers and oligomers), and combinations thereof.

Non-limiting examples of suitable ethylenically unsaturated monomer compounds include styrene and styrene derivatives like alpha-methylstyrene, vinyltoluene, indene, divinylbenzene, vinylpyrrolidone, vinyl siloxane, vinyl caprolactam, stilbene, and also diallyl phthalate, dibenzylidene acetone, allyl benzene, methyl methacrylate, methyl acrylate, (meth) acrylic acid, diacrylate, dimethacrylate, acrylamide, vinyl acetate, triallyl cyanurate, triallyl isocyanurate, allyl compounds such as (di) ethylene glycol diallyl carbonate, chlorostyrene, tert-butylstyrene, tert-butyl acrylate, butanediol dimethacrylate and mixtures thereof. Suitable examples of (meth) acrylate reactive diluents are PEG200 di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 3-butanediol di (meth) acrylate, 2, 3-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate and isomers thereof, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, glycerol di (meth) acrylate, trimethylolpropane di (meth) acrylate, neopentyl glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, PPG250 di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, and mixtures thereof, Tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycidyl (meth) acrylate, (bis) maleimide, (bis) citraconimide, (bis) itaconimide, and mixtures thereof.

The amount of ethylenically unsaturated monomer in the pre-accelerated curable resin according to the present invention is preferably at least 0.1 wt%, more preferably at least 1 wt%, and most preferably at least 5 wt%, based on the weight of the curable resin component. The amount of ethylenically unsaturated monomer is preferably not more than 50 wt%, more preferably not more than 40 wt%, and most preferably not more than 35 wt%.

If the accelerator solution is used to cure a curable resin or to prepare a pre-accelerated resin, the amount of accelerator solution generally used is at least 0.01 wt%, preferably at least 0.1 wt%, and preferably no more than 5 wt%, more preferably no more than 3 wt% of accelerator solution based on the weight of curable resin.

Peroxides and their use in the preparation of pharmaceutical preparations

Peroxides suitable for use in cooperation with the accelerator solution according to the invention for curing curable resins and suitable for being present in the second component of the two-component composition of the invention include inorganic and organic peroxides, such as the conventionally used ketone peroxides, peroxyesters, diaryl peroxides, dialkyl peroxides, and peroxydicarbonates, and also peroxycarbonates, peroxyketals, hydroperoxides, diacylperoxides, and hydrogen peroxide. Preferred peroxides are organic hydroperoxides, ketone peroxides, peroxyesters, and peroxycarbonates. Even more preferred are hydroperoxides and ketone peroxides. Preferred hydroperoxides include cumyl hydroperoxide, 1,3, 3-tetramethylbutyl hydroperoxide, tert-butyl hydroperoxide, isopropylcumyl hydroperoxide, tert-amyl hydroperoxide, 2, 5-dimethylhexyl-2, 5-dihydroperoxide, pinane hydroperoxide, p-menthane hydroperoxide, terpene hydroperoxide and pinene hydroperoxide. Preferred ketone peroxides include methyl ethyl ketone peroxide, methyl isopropyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, and acetylacetone peroxide.

Mixtures of two or more peroxides may also be used. For example, a combination of a hydroperoxide or ketone peroxide with a peroxyester may be used.

Methyl ethyl ketone peroxide, peroxyesters, and/or monoperoxydicarbonate are particularly preferred peroxides for use in the present invention.

The amount of peroxide to be used to cure the curable resin is preferably at least 0.1 parts per hundred resin (phr), more preferably at least 0.5phr, and most preferably at least 1 phr. The amount of peroxide is preferably not more than 8phr, more preferably not more than 5phr and most preferably not more than 2 phr.

Other Components

The accelerator solution, curable resin and peroxide described above may be combined with any of the other additives commonly used in the art of peroxide cured resins, such as fillers, fibers, pigments, phlegmatizers, inhibitors (e.g., inhibitors of oxidative, thermal and/or ultraviolet degradation), lubricants, thixotropic agents, adjuvants and accelerators.

Examples of suitable phlegmatizers include hydrophilic esters and hydrocarbon solvents.

Examples of suitable fibers include glass fibers, carbon fibers, polymer fibers (e.g., aramid fibers), natural fibers, and the like, and combinations thereof. The fibers may be in any suitable form, including in the form of a mat, a tow, and other such forms known in the art.

Examples of suitable fillers include quartz, sand, silica, aluminum hydroxide, magnesium hydroxide, chalk, calcium hydroxide, clays, carbon black, titanium dioxide and lime, and organic fillers such as thermoplastics and rubbers.

Curing of the resin

Curing of the curable resin according to the present invention may generally be initiated by combining an accelerator solution, a peroxide and a curable resin.

The amount of accelerator solution relative to the amount of curable resin may vary as may be desired or needed depending on the particular transition metal(s), organic ligand(s) and curable resin(s) used and the particular cure characteristics (cure curve, including exotherm peak time) of the formulation and the properties of the cured resin sought. For example, the transition metal loading may be about 50 to about 200ppm and the ligand loading may be about 1000 to about 5000ppm based on the weight of the curable resin.

Due to the storage stability of the accelerator solution of the invention, it is possible to premix the curable resin and the accelerator solution several days or weeks before the peroxide is added and thus the actual curing process is started. This allows for the production and sale of curable resin compositions already containing the accelerator on a commercial scale. The present invention also contemplates a two-component system comprising a first component and a second component, wherein the first component comprises at least one pre-accelerated curable resin (a combination of at least one curable resin and at least one accelerator solution according to the present invention) and the second component comprises at least one peroxide. As used herein, the term "two-component system" refers to the following system: wherein the two components (a and B) are physically separated from each other (e.g., in separate cartridges, compartments, totes (totes), drums, or other containers), wherein components a and B are physically combined (mixed) when the system is used to form a cured resin.

The invention may also be practiced with a three component system where the curable resin, peroxide and accelerator solution are physically separated from each other until such time as it is desired to produce a cured resin, where at such time the three components are mixed together and the mixture is cured (polymerized) due to chemical interaction between the curable resin, peroxide and accelerator solution.

The peroxide may be mixed with the pre-accelerated curable resin, added to a pre-mix of the curable resin and the accelerator solution, or pre-mixed with the resin followed by addition of the accelerator solution. The resulting mixture is mixed and dispersed. Depending on the initiator system, the accelerator system, any compounds or substances present to modify the cure rate, and the curable resin composition to be cured, the curing process may be carried out at any temperature from-15 ℃ up to 250 ℃. In one embodiment, the curing process is performed at ambient temperatures commonly used in applications such as hand lay-up (hand-up), spray-up (spray-up), filament winding, resin transfer molding, coating (e.g., gel coating and standard coating), in-mold coating (in-mold coating), button production (button production), centrifugal casting, corrugated or flat sheets, re-lining systems, kitchen sinks via pouring compounds, and the like. However, the present invention may also be used in SMC, BMC, pultrusion (pultrusion) techniques, etc., wherein temperatures up to 180 ℃, more preferably up to 150 ℃, most preferably up to 100 ℃ are used.

The cured resin may be subjected to post-cure treatment to further optimize hardness and/or other properties. Such post-curing treatment is generally carried out at a temperature in the range of 40 ℃ to 180 ℃ for 30min to 15 hours.

End use and application

The cured resins are useful in a variety of applications, including marine applications (including ships and marine sporting products like ship parts), chemical anchoring, roofing, construction, relining, pipes and troughs, flooring, windmill blades, wall panels, composite rebar, laminates, composite articles (including fiber reinforced composite articles), electrical and electronic devices, transportation vehicles such as truck and automotive parts, aerospace, vehicles, and the like.

Exemplary aspects of the invention

Various exemplary aspects of the invention may be summarized as follows:

aspect 1: an accelerator solution comprising, consisting essentially of, or consisting of:

a) at least one transition metal complex of at least one transition metal and at least one organic ligand, the at least one transition metal being selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt, the at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety; and

b) at least one solvent.

Aspect 2: the accelerator solution of aspect 1, wherein the at least one transition metal is selected from the group consisting of: fe. Cu, Zn and Ni.

Aspect 3: the accelerator solution of aspect 1 or 2, wherein the at least one organic ligand comprises at least one moiety selected from the group consisting of:

formula (I): -X-C-C-SH, wherein X is N, NH or NH₂and-X-C-is part of an aliphatic or saturated, unsaturated or aromatic ring structure;

formula (II): -X-C (═ S) -X¹-, where X is S, SH, N or NH, X¹Is NH or NH₂And the-X-C-X1-moiety is part of an aliphatic or saturated, unsaturated or aromatic ring structure; or

Formula (III): -S-C (C ═ S) -S-.

Aspect 4: the accelerator solution of any of aspects 1 to 3, wherein the at least one organic ligand comprises at least one moiety selected from the group consisting of: h₂N-C-C-SH, -N-C-SH, H, in which N and C are part of an aromatic ring₂N-C (═ S) -, and-NH-C (═ S) -.

Aspect 5: the accelerator solution of any one of aspects 1 to 4, wherein the at least one ligand is selected from the group consisting of: mercaptopyridine, acetylthiourea, trithiocyanuric acid, rhodanine, cysteamine, 2-imino-4-thiobiuret, bis (carboxymethyl) trithiocarbonate and thiourea, and deprotonated derivatives thereof.

Aspect 6: the accelerator solution of any one of aspects 1 to 5, wherein the accelerator solution is free of Co.

Aspect 7: the accelerator solution of any one of aspects 1 to 6, wherein the accelerator solution additionally comprises at least one base or at least one carboxylic acid.

Aspect 8: the accelerator solution of any one of aspects 1 to 7, wherein the accelerator solution additionally comprises at least one nitrogen-containing base or at least one saturated aliphatic carboxylic acid.

Aspect 9: the accelerator solution of any of aspects 1 to 8, wherein the composition additionally comprises at least one ethoxylated amine or at least one C1-C6 aliphatic carboxylic acid.

Aspect 10: the accelerator solution of any one of aspects 1 to 9, wherein the complex has been prepared by a process comprising combining a transition metal salt with at least one organic ligand comprising at least one S-C-N, S-C-N, or S-C (═ S) -S moiety in the presence of at least one solvent.

Aspect 11: the accelerator solution of any of aspects 1 to 10, wherein the complex has been prepared by a process comprising combining a transition metal salt with at least one organic ligand in the presence of at least one solvent, the at least one organic ligand comprising at least one moiety selected from:

formula (I): -X-C-C-SH, wherein X is N, NH or NH₂and-X-C-is part of an aliphatic or saturated, unsaturated or aromatic ring structure;

formula (II): -X-C (═ S) -X¹-, where X is S, SH, N or NH, X1 is NH or NH₂And the-X-C-X1-moiety is part of an aliphatic or saturated, unsaturated or aromatic ring structure; or

Formula (III): -S-C (═ S) -S-.

Aspect 12: the accelerator solution of any one of aspects 1 to 11, wherein the at least one solvent is selected from the group consisting of: alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, aldehydes, ketones, ethers, esters, phosphates, carboxylic acids, amides, sulfoxides and N-alkylpyrrolidones, and combinations thereof.

Aspect 13: the accelerator solution of any one of aspects 1 to 12, wherein the at least one solvent is selected from the group consisting of aliphatic polyols.

Aspect 14: the accelerator solution of any one of aspects 1 to 13, wherein the transition metal complex is selected from the group consisting of: acetyl thiourea complexes of Fe; acetyl thiourea complexes of Cu; acetyl thiourea complexes of Zn; a thiocyanuric acid (thiocyanuric acid) complex of Fe; a thiocyanuric acid complex of Cu; rhodanine complexes of Fe; rhodanine complexes of Cu; a cysteamine complex of Cu; 2- (butylamino) ethanethiol (butylcysteamine or BuCysA) complex of Cu, bis (carboxymethyl) trithiocarbonate (CMTTC) complex of Cu, mercaptopyridine complex of Zn, mercaptopyridine complex of Fe, and iminothiobiuret complex of Cu.

Aspect 15: a method of curing a curable resin, the method comprising combining the curable resin with at least one peroxide and at least one accelerator solution according to any one of aspects 1 to 14.

Aspect 16: the method of aspect 15, wherein the at least one peroxide is selected from the group consisting of organic peroxides.

Aspect 17: the method of aspect 15, wherein the at least one peroxide is selected from the group consisting of: ketone peroxides, peroxyesters, diaryl peroxides, dialkyl peroxides, peroxydicarbonates, peroxycarbonates, peroxyketals, hydroperoxides, diacylperoxides, and hydrogen peroxide.

Aspect 18: the method of aspect 15, wherein the at least one peroxide comprises at least one peroxide selected from the group consisting of: ketone peroxides, peroxyesters and/or monoperoxydicarbonates.

Aspect 19: the method of aspect 15, wherein the at least one peroxide comprises methyl ethyl ketone peroxide.

Aspect 20: the method of aspect 15, wherein the at least one peroxide is a liquid at 25 ℃.

Aspect 21: the method of any one of aspects 15 to 20, wherein the curable resin is selected from the group consisting of: alkyd resins, unsaturated polyester resins, vinyl ester resins, and (meth) acrylate resins.

Aspect 22: the method of any one of aspects 15 to 21, wherein the curable resin is selected from the group consisting of unsaturated polyester resins.

Aspect 23: a cured resin obtained by the method of any one of aspects 15 to 22.

Aspect 24: a method for preparing an accelerator solution, the method comprising reacting at least one transition metal salt comprising at least one of Fe, Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt with at least one organic ligand comprising at least one S-C-N, S-C-N, or S-C (═ S) -S moiety in an organic solvent so as to form at least one transition metal complex from the at least one transition metal salt and the at least one organic ligand.

Aspect 25: an accelerator solution obtained by the method of aspect 24.

Aspect 26: a pre-accelerated curable resin comprising at least one curable resin and at least one accelerator solution according to any one of aspects 1 to 14.

Aspect 27: a two-component system comprising a first component and a second component, wherein the first component comprises at least one pre-accelerated curable resin according to aspect 26 and the second component comprises at least one peroxide.

Aspect 28: a cured resin composition comprising a cured resin and at least one transition metal complex of at least one transition metal and at least one organic ligand, the at least one transition metal being selected from the group consisting of: fe. Cu, Zn, Ni, Mn, Cr, Sn, Au, Pd and Pt, the at least one organic ligand comprising at least one S-C-N, S-C-N or S-C (═ S) -S moiety.

In this specification, embodiments have been described in a manner that enables a clear and concise specification to be written, but it is intended and will be understood that embodiments may be variously combined or separated without departing from the invention. For example, it will be understood that all of the preferred features described herein apply to all of the aspects of the invention described herein.

In some embodiments, the invention herein may be construed as excluding any element or method step that does not substantially affect the basic and novel characteristics of the accelerator solution, the pre-accelerated curable resin or the two-component system or the methods used to make or use the accelerator solution, the pre-accelerated curable resin or the two-component system. Additionally, in some embodiments, the invention may be construed as not including any elements or method steps not specified herein.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

Examples of the invention

General experimental methods:

an accelerator solution was first prepared by mixing the metal salts (Fe sulfate, Cu acetate, or Zn 2-ethylhexanoate), organic ligand, 1g diethylene glycol, and other additives, if present. The mixture was stirred at 45 ℃ for 30min, and then cooled to room temperature. The accelerator solution was then transferred and admixed with 25g of UP resin (C)2036C-Ashland, Inc. (Ashland)) and 0.5g (2 phr relative to the resin) of Methyl Ethyl Ketone Peroxide (MEKP) from Arkema, Inc. (Arkema Inc.)DDM-9) were mixed in a paper cup. The resulting mixture was then quickly transferred to a test tube and a thermocouple (to allow monitoring of temperature over time to produce a time-dependent temperature profile of polymerization) was placed in the center of the tube and the assembly was allowed to cure at ambient temperature. This experiment allows the measurement of the peak time and temperature of the exotherm as well as the gelation time. The gelation time (gel time) is the time at which the experiment begins and the temperature reaches above room temperatureThe time elapsed between the time of 5.6 ℃ in minutes.

Example 1:

this example includes the use of about 80% of the FeSO heptahydrate in mineral spirits₄(Fe Sulf), Cu (II) acetate (CuAc)₂) Or 2-ethylhexanoic acid Zn (II) (Zn hex)₂) And an accelerator solution prepared from one of the following organic ligands: acetylthiourea (AcTU), cysteamine (CysA), 2- (butylamino) ethanethiol (butylcysteamine or BuCysA), Rhodanine (RN), thiocyanuric acid (TCA), 2-imino-4-thiobiuret (ITB), bis (carboxymethyl) trithiocarbonate (CMTTC), and Thiourea (TU). In some of these experiments Diisopropylethylamine (DIPEA) was added as a base in an amount corresponding to 1 or 2 equivalents relative to the amount of organic ligand. The amount of the metal salt was 0.014g of Fe sulf and 0.009g of CuAc₂And 0.016g of Zn hex₂Which corresponds to 2mmol metal per kg curable resin. The amount of sulfur-containing ligand was 0.1g, which corresponds to 10 wt% with respect to the accelerator solution and 0.4 wt% with respect to the curable resin. The metal salt, ligand, and DIPEA (in some entries) were mixed with 1g of diethylene glycol to prepare an accelerator solution, which was then used to cure UP resins with MEKP initiator according to the procedure discussed in the general experimental methods section above.

The results of these experiments are disclosed in table 1. The control (comparative or "comp") experiment (entries 1-3) in which the metal salt was examined alone showed that Fe, Cu and Zn metals alone (i.e., in the absence of organic ligands) did not promote the MEKP to cure UP in 2 hours. Entries 4-17 show examples of metal/ligand combinations that unexpectedly produce cured resins within 2 hours.

Table 1.

Example 2 (of the invention):

this example includes the use of Cu (II) acetate (CuAc) with or without Diethanolamine (DEA), with or without Butyric Acid (BA)₂) Of cystamine (CysA)Accelerator solutions prepared in various combinations. All these accelerator combinations were made with 1g DEG as solvent. UP cure experiments with these accelerator solutions were performed according to the procedure mentioned in the general experimental methods section above. The results disclosed in table 2 show that the different accelerator solutions obtained in this example are capable of promoting MEKP to cure UP resins with kinetics (i.e., cure rate/gel time) that are controllable and have relatively high exotherm temperatures, which are desirable because they indicate relatively high degrees of polymerization.

Table 2.

Example 3 (of the invention):

this example includes the use of Cu (II) acetate (CuAc) with or without Monoethanolamine (MEA), and with or without Diethanolamine (DEA) as the base₂) And acetylthiourea (AcTU). All these accelerator combinations were made with 1g DEG as solvent. UP cure experiments with these accelerator solutions were performed according to the procedure mentioned in the general experimental methods section above. The results are disclosed in table 3.

Table 3.

Example 4 (of the invention):

this example includes the use of Cu (II) acetate (CuAc)₂) Accelerator solutions prepared from various combinations of bis (carboxymethyl) trithiocarbonate (CMTTC), Monoethanolamine (MEA), and Diethanolamine (DEA). All these accelerator combinations were made with 1g DEG as solvent. UP cure experiments with these accelerator solutions were performed according to the procedure mentioned in the general experimental methods section above. The results are disclosed in Table 4。

Table 4.

Example 5 (of the invention):

this example includes the use of Cu (II) acetate (CuAc)₂) Accelerator solutions prepared in various combinations of Rhodanine (RN), Monoethanolamine (MEA), and Diethanolamine (DEA) as bases. All these accelerator combinations were made with 1g DEG as solvent. UP cure experiments with these accelerator solutions were performed according to the procedure mentioned in the general experimental methods section above. The results are disclosed in table 5.

Table 5.

Example 6 (of the invention):

this example includes the use of Cu (II) acetate (CuAc)₂) Accelerator solutions prepared with various combinations of 2- (butylamino) ethanethiol (butylcysteamine or BuCysA), Monoethanolamine (MEA), and Diethanolamine (DEA). All these accelerator combinations were made with 1g DEG as solvent. UP cure experiments with these accelerator solutions were performed according to the procedure mentioned in the general experimental methods section above. The results are disclosed in table 6.

Table 6.

Example 7 (of the invention):

this example demonstrates the ability of the accelerator system to accelerate a family of peroxides other than methyl ethyl ketone peroxide. The accelerator solution used for these tests used Cu (II) acetate (CuAc) at 0.7mMol/kg resin₂) Relative to the tree0.063% by weight of 2- (butylamino) ethanethiol (butylcysteamine or BuCysA) with respect to the resin, 0.3% by weight of Monoethanolamine (MEA) with respect to the resin, and DEG as a solvent were prepared. UP cure experiments with these accelerator solutions were performed according to the procedure mentioned in the general experimental methods section above. The results are disclosed in table 7.

Table 7.

This table demonstrates that an accelerator system based on butylcysteamine is able to cure hydroperoxides, peroxyesters and monoperoxydicarbonates at ambient temperature, but not the peroxyketals.