Abstract:
A two-component initiator system having accelerators for curing polymerizable materials comprising the following components: (a) a hydroperoxide compound containing one or more hydroperoxide groups that are bound to a tertiary carbon; (b) a thiourea derivative; and (c) as accelerator, a copper compound which is soluble in the preparation is preferably free of amine and is particularly suited for polymerizable dental compositions.

Description:
[0001]     The invention relates to a novel, two-component initiator system having accelerators for curing polymerizable materials.  
       BACKGROUND OF THE INVENTION  
       [0002]     Two-component initiator systems for curing polymerizable materials are known: 
        1. Benzoyl peroxide/tertiary aromatic amine: Of the peroxides that can be initiated using amines, dibenzoyl peroxide exhibits the highest thermal stability. However, continuous heating of the preparations results in the rapid onset of spontaneous curing. In addition, the slow oxidation of the amines results in yellowish-brown discoloration and impairs the appearance, which is disadvantageous for dental applications. In an acidic environment, which is necessary in adhesives, the amine is immediately protonated in an acid/base reaction and is thereby deactivated. The two-component system cannot be used under such conditions.     2. Barbituric acid derivatives: Use of the barbituric acid initiator system is favored in dental applications because strong discoloration does not occur afterwards. The second component contains copper and chloride ions which catalyze decomposition of the barbituric acid. Since the system contains no amine, it can also be used under acidic conditions. On account of the low thermal stability the products must always be stored at cool temperatures. The initiator component cannot contain any reactive, crosslinking ingredients, or otherwise spontaneous polymerization occurs.     3. Cumene hydroperoxide/acetylthiourea: An endodontic sealant system has been described in US 2003/0134933 (Pentron). This system contains fairly large quantities (1-10%) of cumene hydroperoxide and acetylthiourea, and possibly traces back to the description of an adhesive in JP 58219281A (Mitsubishi). Very high thermal stability compared to a conventional system was described. However, readjustment of the composition showed unsatisfactorily slow curing kinetics in the lower concentration range. At the lower limit in the description (1% in each case) polymerization completely failed.     4. Cumene hydroperoxide/accelerators: An adhesive according to DE 195 01 933 (Henkel) contains a hydroperoxide as initiator, and as accelerator contains one of the following compounds: sulfimides, hydrazine derivatives, tertiary amines, and salts or complexes of copper. Drying agents may also be contained for accelerating the crosslinking. High reactivity is achieved in individual compositions, but these are strongly colored by the metal salts, display strong yellowing, or exhibit inadequate storage stability.     5. Peroxide/metal compound: A polymerizable composition containing a thermally stable peroxide is described in DE 696 21 500 (Dentsply). In addition to cumene hydroperoxide, the polymerizable system may also contain a metal compound in the form of a thiourea complex. Copper compounds, among others, are described as metal compounds. An acid and an amine must also be contained therein. A powder-liquid system was specifically described in the claims. Although the initiator system as described is apparently functional in an acid-containing environment, the amine contained therein can result in the typical discoloration of such products.     6. EP 1 479 364 A1 describes amine-free two-component dental compositions comprising a thiourea-hydroperoxide initiator system.        
 
         [0009]     Accordingly, the object is to develop an improved system which has short inhibition times and low content of the initiator components, preferably containing no amine in order to prevent discoloration, and which ensures to the greatest extent possible the functionality under acidic conditions.  
       SUMMARY OF THE INVENTION  
       [0010]     Surprisingly, it has been found that catalytic amounts of copper compounds markedly improve the initiator effect of such thiourea-hydroperoxide initiator systems. The object is therefore achieved by an initiator system according to claim  1 , and by compositions containing same according to claim  2 . The subclaims state advantageous embodiments.  
     
    
     DETAILED DESCRIPTION  
       [0011]     The combination of the redox partners cumene hydroperoxide and acetylthiourea in the presence of copper compounds has proven to be particularly suitable. The components, individually and in reactive monomers, can be stored for several months even at high temperatures around 50° C. The low proportions of copper (&lt;0.1%) accelerate the initial redox process so greatly that a concentration of 1% or less of the redox partners is sufficient. Since amine is not contained therein, no subsequent color change has been observed. The pale yellow-green appearance of the polymer depends on the copper concentration, and remains unchanged. The functionality of the two-component system was not adversely affected by the presence of acids.  
         [0012]     The system has the following advantages: 
        a) The composition represents a two-component initiator system having very high storage stability. The composition does not exhibit subsequent discoloration and is not impaired by acids. The inhibition time may be adjusted over a very wide range by varying the copper content. Numerous tests have been carried out for various combinations, and the respective inhibition times determined. The concentrations of cumene hydroperoxide, acetylthiourea, and copper salt were varied. Two copper salts (acetylacetonate, naphthenate) were tested which showed no apparent differences in reactivity. The inhibition times were determined under acidic conditions by combination with phosphoric acid ester (2%, 5%), 4-META (15%), and acrylic acid (5%). The storage stabilities of all preparations were tracked at 50° C. over a period of up to 3 months. The effect of the copper content on the coloration of the polymer was determined, and the color stability was monitored.     b) The initiator system is universally applicable for all radically polymerizable systems. The very good storage stability and the low tendency toward discoloration are particularly advantageous for the production of medical or dental synthetic materials. The possibility of combining with acidic components may open up new fields of application (adhesives, self-etching preparations).     c) Compared to the conventional two-component system composed of dibenzoyl peroxide and a tertiary aromatic amine, the inventive system is characterized by markedly better storage stability, may also be processed under acidic conditions, and exhibits improved color stability.     d) The composition constitutes a redox system, and in the activated state contains a hydroperoxide as oxidation agent and a thiourea derivative as reducing agent. An initiator system as described is known from patents JP 58219281, US 2003/0134933, US 2003/0166740, and EP 1 479364.        
 
         [0017]     It was unexpectedly found that the addition of soluble copper compounds results in an accelerator with greatly improved initiation. Addition of acids does not adversely affect the system, and can even lead to a further increase in the initiation activity. Through the addition of copper compounds it is possible to reduce both the concentration of the activating hydroperoxide component and the proportion of the thiourea derivative while still achieving a suitable inhibition time (processing time). The storage stability of the two-component initiator system is not adversely changed by a proportion of the copper compound, as shown in tests. The pale, yellowish intrinsic color of the polymers consistently remains unchanged.  
         [0018]     The composition of the two-component initiator system according to the invention contains an organic hydroperoxide in one component, whereby the compound may also contain more than one hydroperoxide group. In addition to other compounds, t-butylhydroperoxide, t-amylhydroperoxide, benzene hydroperoxide, pinane hydroperoxide, 1,1,3,3-tetramethylbutylhydroperoxide, 5-phenyl-4-pentenylhydroperoxide, and p-diisopropylbenzene hydroperoxide are suitable, with isopropylbenzene hydroperoxide being particularly suitable.  
         [0019]     A second component contains a thiourea derivative and at least one copper compound. The following are examples of such thiourea derivatives: 
    1-(1,1-Dioxotetrahydrothiophene-3-yl)-1-methyl-3-phenyl-thiourea     1-(1,2-Diphenylethyl)-3-(2,4-xylyl)-2-thiourea     1-(1,2-Diphenylethyl)-3-(4-ethoxyphenyl)-2-thiourea     1-(1,2-Diphenylethyl)-3-(ortho-tolyl)-2-thiourea     1-(1,2-Diphenylethyl)-3-phenyl-2-thiourea     1,1′-(3,3′-Dimethylbiphenyl-4,4′-diyl)bis(3-(2-methylpropyl)-2-thiourea)     1,1,3-Triphenyl-2-thiourea     1,1′-(4,5-Dimethyl-1,2-phenylene)bis(3-phenyl-2-thiourea)     1-(1,5-Dime[thyl]-3-oxo-2-ph[enyl]-2,3-dihydro-1H-pyrazole-4-yl)-3-(2-methylallyl)thiourea     1-(1,5-Dime[thyl]-3-oxo-2-ph[enyl]-2,3-dihydro-1H-pyrazole-4-yl)-3-(3-trif[luoro]me[thyl]ph[enyl])thiourea     1-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-3-phenylthiourea     1,1-Bis-(2-hydroxyethyl)-3-phenylthiourea     1,1-Diallyl-3-(3-chlorobenzo(b)thiophene-2-carbonyl)thiourea     1,1-Diallyl-3-(4-nitrophenyl)-2-thiourea     1,1-Diallyl-3-phenyl-2-thiourea     1,1-Dibenzyl-3-(2,4-dichlorobenzoyl)thiourea     1,1-Dibenzyl-3-(2-(trifluoromethyl)phenyl)-2-thiourea     1,1-Dibenzyl-3-phenyl-2-thiourea     1,1-Dibutyl-3-phenyl-2-thiourea     1,1-Diethyl-3-phenyl-2-thiourea     1,1-Diisobutyl-3-phenyl-2-thiourea     1,1-Diisopropyl-3-phenyl-2-thiourea     1,1-Dimethyl-3-(2,6-xylyl)-2-thiourea     1,1-Dimethyl-3-(2-methoxyphenyl)-2-thiourea     1,1-Dimethyl-3-(3,4-xylyl)-2-thiourea     1,1-Dimethyl-3-(4-ethoxyphenyl)-2-thiourea     1,1-Dimethyl-3-(4-methoxyphenyl)-2-thiourea     1,1-Dimethyl-3-(alpha-(methylimino)benzyl)-2-thiourea     1,1-Dimethyl-3-(meta-tolyl)-2-thiourea     1,1-Dimethyl-3-(ortho-tolyl)-2-thiourea     1,1-Dimethyl-3-(para-tolyl)-2-thiourea     1,1-Dimethyl-3-phenyl-2-thiourea     1,1-Dipropyl-3-phenyl-2-thiourea     1-(1-Ethyl-3-piperidinyl)-3-phenyl-2-thiourea     1-(1-Naphthyl)-2-thiourea     1-(1-Naphthyl)-3-(2-phenoxypropionyl)-2-thiourea     1,1-Pentamethylene-3-phenyl-2-thiourea     1-(2,2-Dimethylpropyl)-3-(2-fluorophenyl)thiourea     1-(2-(2-Hydroxyethoxy)ethyl)-3-phenylthiourea     1-(2,4,6-Tribromophenyl)-2-thiourea     1-(2,4-Dichlorobenzoyl)-3-(1-naphthyl)-2-thiourea     1-(2,4-Dichlorobenzoyl)-3-(7-hydroxy-1-naphthyl)-2-thiourea     1-(2,4-Dichlorophenyl)-2-thiourea     1-(2,4-Difluorophenyl)-3-(2-fluorophenyl)-2-thiourea     1-(2,4-Difluorophenyl)-3-(4-phenoxyphenyl)-2-thiourea     1-(2,4-Difluorophenyl)-3-ethyl-2-thiourea     1-(2,5-Dichlorophenyl)-3-(2-phenoxypropionyl)-2-thiourea     1-(2,5-Dichlorophenyl)-3-dodecanoyl-2-thiourea     1-(2,5-Dichlorophenyl)-3-phenyl-2-thiourea     1-(2,5-Dimethoxyphenyl)-3-(3-nitrobenzoyl)-2-thiourea     1-(2,5-Dimethoxyphenyl)-3-dodecanoyl-2-thiourea     1-(2,5-Dimethoxyphenyl)-3-methyl-2-thiourea     1-(2,5-Dimethoxyphenyl)-3-phenyl-2-thiourea     1-(2,5-Dimethoxyphenyl)-3-propyl-2-thiourea     1-(2,5-Dimethylmorpholino)-3-phenyl-2-thiourea     1-(2,6-Diethylphenyl)-3-(4-hydroxyphenyl)-2-thiourea     1-(2,6-Xylyl)-2-thiourea     1-(2-Bromo-4-methylphenyl)-3-phenylthiourea     1-(2-Bromophenyl)-2-thiourea     1-(2-Carboxyphenyl)-3-phenyl-2-thiourea     1-(2-Chloro-4-methoxyphenyl)-3-cyclohexyl-2-thiourea     1-(2-Chloro-4-nitrophenyl)-3-(3,4-dichlorobenzoyl)-2-thiourea     1-(2-Chloro-4-nitrophenyl)-3-ethyl-2-thiourea     1-(2-Chloro-5-nitrophenyl)-3-dodecanoyl-2-thiourea     1-(2-Chlorobenzoyl)-3-(2,4-difluorophenyl)-2-thiourea     1-(2-Chlorobenzoyl)-3-(2,4-dimethoxyphenyl)-2-thiourea     1-(2-Chlorobenzoyl)-3-(2-fluorophenyl)-2-thiourea     1-(2-Chlorobenzoyl)-3-(2-methoxy-5-methylphenyl)-2-thiourea     1-(2-Chlorobenzoyl)-3-(3,4-dichlorophenyl)-2-thiourea     1-(2-Chlorobenzoyl)-3-(3-chlorophenyl)-2-thiourea     1-(2-Chlorobenzoyl)-3-(4-nitrophenyl)-2-thiourea     1-(2-Chlorobenzoyl)-3-(5-chloro-2-methoxyphenyl)-2-thiourea     1-(2-Chlorobenzyl)-3-cyclohexyl-1-methyl-2-thiourea     1-(2-Chlorophenyl)-3-(2,4-dichlorobenzoyl)-2-thiourea     1-(2-Chlorophenyl)-3-dodecanoyl-2-thiourea     1-(2-Chlorophenyl)-3-phenyl-2-thiourea     1-(2-Ethylphenyl)-3-methyl-2-thiourea     1-(2-Fluorobenzoyl)-3-(4-ethoxyphenyl)-2-thiourea     1-(2-Fluorobenzoyl)-3-(4-fluorophenyl)-2-thiourea     1-(2-(Hexadecylthio)phenyl)-2-thiourea     1-(2-Hydroxy-1-phenylethyl)-3-phenylthiourea     1-(2-Hydroxycyclohexyl)-3-phenylthiourea     1-(2-Hydroxyethyl)-3-(2,4-xylyl)-2-thiourea     1-(2-Hydroxyethyl)-3-phenyl-2-thiourea     1-(2-Methoxy-5-methylphenyl)-1-methyl-3-(2-naphthyl)-2-thiourea     1-(2-Methoxyphenyl)-3-(2-methylbenzoyl)thiourea     1-(2-Methoxyphenyl)-2-thiourea     1-(2-Methoxyphenyl)-2-thiourea     1-(2-Methyl-2-morpholine-4-yl-propyl)-3-phenylthiourea     1-(2-Methylallyl)-3-(6-(3-(2-methylallyl)thioureido)pyridine-2-yl)thiourea     1-(2-Methylbenzoyl)-3-p-tolylthiourea     1-(2-Methylbenzoyl)-3-phenylthiourea     1-(2-Methylbenzoyl)-3-pyrimidine-2-yl-thiourea     1-(2-Morpholinoethyl)-3-phenyl-2-thiourea     1-(2-Naphthyl)-3-phenyl-2-thiourea     1-(2-Nitrophenyl)-3-phenyl-2-thiourea     1-(2-Pyridyl)-3-(3,4-xylyl)-2-thiourea     1-(2-Pyridyl)-3-(ortho-tolyl)-2-thiourea     1-(3-(2-Mercaptoethyl)-3H-benzothiazole-2-ylidene)-2-me[thyl]isothiourea, hydriodide     1-(3,4-Dibromophenyl)-3-phenyl-2-thiourea     1-(3,4-Dichlorobenzoyl)-3-(2,4-difluorophenyl)-2-thiourea     1-(3,4-Dichlorobenzoyl)-3-(2-fluorophenyl)-2-thiourea     1-(3,4-Dichlorobenzoyl)-3-(2-thiazolyl)-2-thiourea     1-(3,4-Dichlorobenzoyl)-3-(3,4-dichlorophenyl)-2-thiourea     1-(3,4-Dichlorobenzoyl)-3-(4-ethoxyphenyl)-2-thiourea     1-(3,4-Dichlorobenzoyl)-3-(4-nitrophenyl)-2-thiourea     1-(3,4-Dichlorobenzoyl)-3-(4-sulfamoyl)phenyl-2-thiourea     1-(3,4-Dichlorophenyl)-2-thiourea     1-(3,4-Dichlorophenyl)-3-(3,5-dinitrobenzoyl)-2-thiourea     1-(3,4-Dichlorophenyl)-3-(4-sulfamoylphenyl)-2-thiourea     1-(3,4-Dichlorophenyl)-3-(diphenylmethyl)-2-thiourea     1-(3,4-Dichlorophenyl)-3-phenyl-2-thiourea     1-(3,4-Dimethoxybenzyl)-3-phenylthiourea     1-(3,4-Dimethoxyphenyl)-2-thiourea     1-(3,5-Dichlorobenzyl)-3-phenyl-2-thiourea     1-(3,5-Dichlorophenyl)-2-thiourea     1-(3-Acetylphenyl)-3-allyl-2-thiourea     1-(3-Acetylphenyl)-3-ethyl-2-thiourea     1,3-Bis(2,6-dichlorophenyl)-2-thiourea     1,3-Bis(2-chlorophenyl)-2-thiourea     1,3-Bis(2-fluorophenyl)-2-thiourea     1,3-Bis-(2-methoxyphenyl)-2-thiourea     1,3-Bis(3-acetylphenyl)-2-thiourea     1,3-Bis(3-bromophenyl)-2-thiourea     1,3-Bis(3-cyanophenyl)-2-thiourea     1,3-Bis(3-iodophenyl)-2-thiourea     1,3-Bis(3-methoxyphenyl)-2-thiourea     1,3-Bis(3-nitrophenyl)-2-thiourea     1,3-Bis(3-pyridylmethyl)-2-thiourea     1,3-Bis(4-bromophenyl)-2-thiourea     1,3-Bis(4-chlorophenyl)-2-thiourea     1,3-Bis(4-cyanophenyl)-2-thiourea     1,3-Bis(4-(dimethylamino)phenyl)-2-thiourea     1-(3-Bromophenyl)-3-(2-methylbenzoyl)thiourea     1-(3-Bromophenyl)-3-(naphthalene-1-carbonyl)thiourea     1-(3-Bromobenzoyl)-3-(3-chlorophenyl)-2-thiourea     1-(3-Butoxypropyl)-3-phenyl-2-thiourea     1-(3-Carboxyphenyl)-2-thiourea     1-(3-Chloro-2-methylphenyl)-3-(3,4,5-trimethoxybenzoyl)thiourea     1-(3-Chloro-2-methylphenyl)-3-(4-fluorobenzoyl)thiourea     1-(3-Chlorobenzo(b)thiophene-2-carbonyl)-3-(4-nitrophenyl)thiourea     1-(3-Chlorobenzyl)-3-phenyl-2-thiourea     1-(3-Chlorophenyl)-2-thiourea     1-(3-Chlorophenyl)-3-(2-fluorobenzoyl)-2-thiourea     1-(3-Chlorophenyl)-3-(3,4-dichlorobenzoyl)-2-thiourea     1-(3-Chlorophenyl)-3-dodecanoyl-2-thiourea     1-(3-Chlorophenyl)-3-phenyl-2-thiourea     1,3-Di-o-tolyl-2-thiourea     1,3-Di-o-tolyl-2-thiourea     1,3-Di-p-tolyl-2-thiourea     1,3-Di-tert-butyl-2-thiourea     1,3-Diallyl-2-thiourea     1,3-Dibenzyl-2-thiourea     1-(3-(Dibutylamino)propyl)-3-phenyl-2-thiourea     1,3-Dicyclohexyl-2-thiourea     1,3-Didecyl-2-thiourea     1,3-Didodecyl-2-thiourea     1,3-Difurfuryl-2-thiourea     1,3-Diheptyl-2-thiourea     1,3-Dihexadecyl-2-thiourea     1,3-Dihexyl-2-thiourea     1,3-Diisopropyl-2-thiourea     1,3-Dioctyl-2-thiourea     1,3-Dipropyl-2-thiourea     1,3-Ditetradecyl-2-thiourea     1-(3-Fluorophenyl)-3-(3-nitrobenzoyl)-2-thiourea     1-(3-Fluorophenyl)-3-methyl-2-thiourea     1-(3-Hydroxyphenyl)-3-(4-nitrophenyl)-2-thiourea     1-(3-Hydroxyphenyl)-3-phenyl-2-thiourea     1-(3-Methoxyphenyl)-3-(2-methylbenzoyl)thiourea     1-(3-Methoxyphenyl)-3-(naphthalene-1-carbonyl)thiourea     1-(3-Methoxypropyl)-2-thiourea     1-(3-Nitrophenyl)-3-(3-phenylacryloyl)thiourea     1-(3-Nitrophenyl)-3-phenyl-2-thiourea     1-(3-Phenylpropionyl)-3-(2,3-xylyl)-2-thiourea     1-(3-Pyridyl)-2-thiourea     1-(3-(Trifluoromethyl)phenyl)-2-thiourea     1-(3-Trifluoromethylphenyl)-3-(2,3,4-trimethoxybenzoyl)thiourea     1-(3H-benzothiazole-2-ylidene)-2-benzylisothiourea     1-(4-Acetamidophenyl)-3-(2-butenoyl)-2-thiourea     1-(4-Acetamidophenyl)-3-(2-phenoxyacetyl)-2-thiourea     1-(4-Acetamidophenyl)-3-ethyl-2-thiourea     1-(4-Acetylphenyl)-3-methyl-2-thiourea     1-(4-Bromophenyl)-3-(2,4-dichlorobenzoyl)thiourea     1-(4-Chloro-2,5-dimethoxyphenyl)-3-(4-nitrophenyl)-2-thiourea     1-(4-Chloro-2,5-dimethoxyphenyl)-3-methyl-2-thiourea     1-(4-Chloro-2-methylphenyl)-3-(2-methyl-3-phenylacryloyl)thiourea     1-(4-Chloro-2-methylphenyl)-3-dodecanoyl-2-thiourea     1-(4-Chloro-7-methoxy-2-quinolyl)-3-phenyl-2-thiourea     1-(4-Chlorophenyl)-3-(4-nitrobenzoyl)thiourea     1-(4-Chlorophenyl)-3-(naphthalene-1-carbonyl)thiourea     1-(4-Chlorobenzyl)-1-methyl-3-phenyl-2-thiourea     1-(4-Chlorophenyl)-2-thiourea     1-(4-Chlorophenyl)-3-(2-pyridyl)-2-thiourea     1-(4-Chlorophenyl)-3-(4-diethylamino-ortho-tolyl)-2-thiourea     1-(4-Chlorophenyl)-3-phenyl-2-thiourea     1-(4-Difluoromethoxy-2-formylphenyl)-3-(1,2,2-trimethylpropyl)thiourea     1-(4-Difluoromethoxyphenyl)-3-(1,2,2-trimethylpropyl)thiourea     1-(4-Difluoromethylsulfanylphenyl)-3-(1,2,2-trimethylpropyl)thiourea     1-(4-(Dimethylamino)phenyl)-3-(4-nitrophenyl)-2-thiourea     1-(4-(Dimethylamino)phenyl)-3-dodecanoyl-2-thiourea     1-(4-(Dimethylamino)phenyl)-3-(phenyl)-2-thiourea     1-(4-Ethoxycarbonyl)-3-ethyl-2-thiourea     1-(4-Ethoxyphenyl)-3-(1-naphthylcarbonyl)-2-thiourea     1-(4-Ethoxyphenyl)-3-(2-pyridyl)-2-thiourea     1-(4-Ethoxyphenyl)-3-(3-nitrobenzoyl)-2-thiourea     1-(4-Ethoxyphenyl)-3-ethyl-2-thiourea     1-(4-Ethylphenyl)-3-phenyl-2-thiourea     1-(4-Fluorophenyl)-3-(2,4,6-trimethylphenyl)-2-thiourea     1-(4-Fluorophenyl)-3-(3-nitrobenzoyl)-2-thiourea     1-(4-(Hexadecylsulfonyl)phenyl)-2-thiourea     1-(4-Hydroxyphenyl)-3-propyl-2-thiourea     1-(4-Iodophenyl)-3-(3-phenylpropionyl)-2-thiourea     1-(4-Me[th]o[xy]ph[enyl])-3-((4-me[th]o[xy]phenyl)-(toluene-4-sulfonylmethylimino)methyl)thiourea     1-(4-Methoxybenzyl)-3-phenylthiourea     1-(4-Methoxyphenyl)-3-(4-methylbenzoyl)thiourea     1-(4-Methoxyphenyl)-3-phenylthiourea     1-(4-Methoxyphenyl)-3-(2-pyridyl)-2-thiourea     1-(4-Methoxyphenyl)-3-(2-pyridyl)-2-thiourea     1-(4-Methylbenzyl)-3-phenyl-2-thiourea     1-(4-Nitrobenzoyl)-3-pyridine-2-yl-methylthiourea     1-(4-Nitrophenyl)-2-thiourea     1-(4-Nitrophenyl)-3-(3-(trifluoromethyl)phenyl)-2-thiourea     1-(4-Nitrophenyl)-3-phenyl-2-thiourea     1-(4-Pyridylmethyl)-3-(2,6-xylyl)-2-thiourea     1-(4-tert-Butylphenyl)-2-thiourea     1-(4-Trifluoromethoxyphenyl)-3-(1,2,2-trimethylpropyl)thiourea     1-(4-Trifluoromethylsulfanylphenyl)-3-(1,2,2-trimethylpropyl)thiourea     1-(5-Anilino-1,2,4-thiadiazole-3-yl)-3-phenyl-2-thiourea     1-(5-Bromo-3-methylpyridine-2-yl)-3-phenylthiourea     1-(5-Chloro-2,4-dimethoxyphenyl)-3-(2,4-difluorophenyl)-2-thiourea     1-(5-Chloro-2,4-dimethoxyphenyl)-3-(2,5-dimethoxyphenyl)-2-thiourea     1-(5-Chloro-2,4-dimethoxyphenyl)-3-(2-fluorophenyl)-3-methyl-2-thiourea     1-(5-Chloro-2,4-dimethoxyphenyl)-3-methyl-2-thiourea     1-(5-Chloro-2-methoxyphenyl)-3-(3,4-dichlorobenzoyl)-2-thiourea     1-(5-Chloro-2-methoxyphenyl)-3-phenyl-2-thiourea     1-(5-Hydroxy-1-naphthyl)-3-phenyl-2-thiourea     1-Acetyl-3-phenyl-2-thiourea     1-Allyl-3-(1,2-diphenylethyl)-2-thiourea     1-Allyl-3-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-yl)thiourea     1-Allyl-3-(1-naphthyl)-2-thiourea     1-Allyl-3-(1-naphthylmethyl)-2-thiourea     1-Allyl-3-(2-(1-hydroxyethyl)phenyl)-2-thiourea     1-Allyl-3-(2-ethoxyphenyl)-2-thiourea     1-Allyl-3-(3-chloro-2-methylphenyl)-2-thiourea     1-Allyl-3-(3-hydroxyphenyl)-2-thiourea     1-Allyl-3-(4-chlorobenzyl)-2-thiourea     1-Allyl-3-(4-chlorophenyl)-2-thiourea     1-Allyl-3-(4-hydroxyphenyl)-2-thiourea     1-Allyl-3-(diphenylmethyl)-2-thiourea     1-Allyl-3-morpholine-4-yl-thiourea     1-Allyl-3-o-tolylthiourea     1-Allyl-3-octadecyl-2-thiourea     1-Allyl-3-phenyl-2-thiourea     1-(alpha-Methylbenzyl)-3-(4-pyridylmethyl)-2-thiourea     1-(alpha-Methylbenzyl)-3-phenylthiourea     1-Amidino-2-thiourea oxalate     1-Amidino-3-(4-bromophenyl)-2-thiourea     1-Amidino-3-benzoyl-2-thiourea     1-Amidino-3-methyl-2-thiourea p-toluenesulfonate     1-Amidino-3-(p-tolyl)-2-thiourea     1-Amidino-3-propyl-2-thiourea     1-Amidino-3-propyl-2-thiourea p-toluenesulfonate     1-Benzothiazole-2-yl-3-phenylthiourea     1-Benzoyl-3-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-yl)thiourea     1-Benzoyl-3-(1,5-dimethyl-3-oxo-2-phenylpyrazolidine-4-yl)thiourea     1-Benzoyl-3-(2,4,6-trimethylphenyl)thiourea     1-Benzoyl-3-(2,6-dichlorophenyl)-2-thiourea     1-Benzoyl-3-(2-chlorobenzyl)thiourea     1-Benzoyl-3-(2-chlorophenyl)-2-thiourea     1-Benzoyl-3-(3,4-dimethoxyphenethyl)-2-thiourea     1-Benzoyl-3-(4-dimethylaminophenyl)thiourea     1-Benzoyl-3-(4-methoxy-2-nitrophenyl)-2-thiourea     1-Benzoyl-3-(4-morpholine-4-yl-phenyl)thiourea     1-Benzoyl-3-(4-nitrophenyl)-2-thiourea     1-Benzoyl-3-(4-oxothiazolidine-2-ylidene)thiourea     1-Benzoyl-3-(alpha,alpha,alpha-trifluoro-ortho-tolyl)-2-thiourea     1-Benzoyl-3-p-tolylthiourea     1-Benzoyl-3-phenyl-2-thiourea     1-Benzoyl-3-pyridine-2-yl-methylthiourea     1-(Benzoylamidino)-2-thiourea     1-Benzyl-1-butyl-3-phenyl-2-thiourea     1-Benzyl-1-ethyl-3-phenyl-2-thiourea     1-Benzyl-2-thiourea     1-Benzyl-3-(2-methylbenzoyl)thiourea     1-Benzyl-3-(2-phenoxypropionyl)-2-thiourea     1-Benzyl-3-(4-chloro-2-(trifluoromethyl)phenyl)-2-thiourea     1-Benzyl-3-(4-fluoro-3-nitrophenyl)-2-thiourea     1-Benzyl-3-(4-trifluoromethylsulfanylphenyl)thiourea     1-Benzyl-3-cinnamoyl-2-thiourea     1-Benzyl-3-cyclohexyl-1-ethyl-2-thiourea     1-Benzyl-3-furfuryl-2-thiourea     1-Benzyl-3-methyl-2-thiourea     1-Benzyl-3-phenyl-2-thiourea     1-Butyl-2-thiourea     1-Butyl-3-(2-pyridyl)-2-thiourea     1-Butyl-3-(4-isopropylphenyl)-2-thiourea     1-Butyl-3-phenyl-2-thiourea     1-Cinnamoyl-3-(4-ethoxyphenyl)-2-thiourea     1-Cinnamoyl-3-(4-hydroxyphenyl)-2-thiourea     1-Cyano-3-methylisothiourea, sodium salt     1-Cyclododecyl-3-(4-ethoxyphenyl)-2-thiourea     1-Cyclohexyl-1-methyl-3-phenyl-2-thiourea     1-Cyclohexyl-3-(2-ethoxyphenyl)-2-thiourea     1-Cyclohexyl-3-(2-morpholinoethyl)-2-thiourea     1-Cyclohexyl-3-(4-ethoxyphenyl)-2-thiourea     1-Cyclohexyl-3-phenyl-2-thiourea     1-Cyclopentyl-3-phenyl-2-thiourea     1-Diphenylmethyl-3-(2-phenethyl)-2-thiourea     1-Dodecanoyl-2-thiourea     1-Dodecanoyl-3-(1-naphthyl)-2-thiourea     1-Dodecanoyl-3-(2-ethoxyphenyl)-2-thiourea     1-Dodecanoyl-3-(2-methoxy-4-nitrophenyl)-2-thiourea     1-Dodecanoyl-3-(2-methyl-4-nitrophenyl)-2-thiourea     1-Dodecanoyl-3-(2-methyl-5-nitrophenyl)-2-thiourea     1-Dodecanoyl-3-(2-naphthyl)-2-thiourea     1-Dodecanoyl-3-(2-pyrimidinyl)-2-thiourea     1-Dodecanoyl-3-(2-(trifluoromethyl)phenyl)-2-thiourea     1-Dodecanoyl-3-(4-methoxyphenyl)-2-thiourea     1-Dodecanoyl-3-(4-(N-methylacetamido)phenyl)-2-thiourea     1-Dodecyl-3-phenyl-2-thiourea     1-Ethyl-3-(2-fluorophenyl)-2-thiourea     1-Ethyl-3-(2-methoxy-5-methylphenyl)-2-thiourea     1-Ethyl-3-(3,4-xylyl)-2-thiourea     1-Ethyl-3-(4-nitrophenyl)-2-thiourea     1-Ethyl-3-(m-tolyl)-2-thiourea     1-Ethyl-3-(p-tolyl)-2-thiourea     1-Ethyl-3-phenyl-2-thiourea     1-(Furan-2-carbonyl)-3-(2-trifluoromethylphenyl)thiourea     1-(Furan-2-carbonyl)-3-(5-methylpyridine-2-yl)thiourea     1-(Furan-2-carbonyl)-3-furan-2-yl-methylthiourea     1-Furan-2-yl-methyl-3-(2-methylbenzoyl)thiourea     1-Furan-2-yl-methyl-3-(4-(1,1,2,2,3,3,3-heptafluoropropylsulfanyl)-ph[enyl])thiourea     1-Furan-2-yl-methyl-3-(4-nitrobenzoyl)thiourea     1-Furfuryl-3-(1-naphthyl)-2-thiourea     1-Furfuryl-3-phenyl-2-thiourea     1-Hexadecanoyl-2-thiourea     1-Hexadecyl-3-phenyl-2-thiourea     1-(Hexamethyleneimino)-3-(3-(trifluoromethyl)phenyl)-2-thiourea     1-Isobutyl-3-phenyl-2-thiourea     1-Isopropyl-3-(1-naphthyl)-2-thiourea     1-Isopropyl-3-(3-(trifluoromethyl)phenyl)-2-thiourea     1-(Isopropyl)-3-(4-methyl-3-nitrophenyl)-2-thiourea     1-Isopropyl-3-phenyl-2-thiourea     1-Methallyl-3-methyl-2-thiourea     1-Methyl-1-(4-octyloxyphenyl)-2-thiourea     1-Methyl-3-(2,4,5-trichlorophenyl)-2-thiourea     1-Methyl-3-(2,6-xylyl)-2-thiourea     1-Methyl-3-phenyl-2-thiourea     1-Methyl-3-propyl-2-thiourea     1-(Naphthalene-1-carbonyl)-3-m-tolylthiourea     1-(Naphthalene-1-carbonyl)-3-phenylthiourea     1-(Naphthalene-2-carbonyl)-3-(3-nitrophenyl)thiourea     1-(Naphthalene-2-carbonyl)-3-p-tolylthiourea     1-Octadecyl-3-phenyl-2-thiourea     1-Phenethyl-3-phenyl-2-thiourea     1-Phenyl-3-(1,2,4)triazole-4-yl-thiourea     1-Phenyl-3-(2-(2-pyridyl)ethyl)-2-thiourea     1-Phenyl-3-(2-(3-phenylthioureido)cyclohexyl)thiourea     1-Phenyl-3-(2,6-xylyl)-2-thiourea     1-Phenyl-3-(2-pyridyl)-2-thiourea     1-Phenyl-3-(2-thiazolyl)-2-thiourea(2)     1-Phenyl-3-(3-pyridyl)-2-thiourea     1-Phenyl-3-(3-pyridylmethyl)-2-thiourea     1-Phenyl-3-(4-(3-phenylthioureido)phenyl)thiourea     1-Phenyl-3-(4-trifluoromethylbenzyl)thiourea     1-Phenyl-3-(5-phenyl-1,2,4-thiadiazole-3-yl)-2-thiourea     1-Phenyl-3-(p-tolyl)-2-thiourea     1-Phenyl-3-(p-tolylsulfonyl)-2-thiourea     1-Phenyl-3-propyl-2-thiourea     1-Phenyl-3-tetradecyl-2-thiourea     1-Pyridine-3-yl-methyl-3-(2-trifluoromethylphenyl)thiourea     1-tert-Butyl-3-phenylthiourea     2-(1,1-Dioxo-2,5-dihydro-1H-thiophene-3-yl-methyl)isothiourea,hydrochloride     2-(2-Aminoethyl)isothiourea     2-(2-Cyanoethyl)isothiourea     2-(3-Carbamimidoylsulfanyl-me[thyl]-2,4,6-trime[thyl]benzyl)isothiourea     2-(3-Carbamimidoylsulfanylmethylbenzyl)isothiourea     2-(3-Carbamimidoylsulfanylmethylbenzyl)isothiourea     (2,3-Difluorophenyl)thiourea     (2,3-Dimethylphenyl)thiourea     2-(3-Phenylbutyl)isothiourea     (2,4,6-Trimethylphenyl)thiourea     2-(4-Carbamimidoylsulfanylmethylbenzyl)isothiourea     2-(4-Carbamimidoylsulfanylmethylbenzyl)isothiourea     (2,4-Difluorophenyl)thiourea     2-(4-Hydroxy-1,1-dioxotetrahydrothiophene-3-yl)isothiourea     2-(4-Me[thyl]-1,1-dioxo-4H-thiophene-3-yl)isothiourea     2-(4-Methyl-1,1-dioxo-2,3-dihydro-1H-thiophene-3-yl)isothiourea     2-(4-Methyl-1,1-dioxo-2,5-dihydro-1H-thiophene-3-yl)isothiourea     (2,5-Difluorophenyl)thiourea     2-(6-Carbamimidoylsulfanyl-me[thyl]naphthalene-2-yl-me[thyl])isothiourea     (2,6-Difluorophenyl)thiourea     2-Benzoylisothiourea     2-Benzyl-1-(3-(2-mercaptoethyl)-3H-benzothiazole-2-ylidene)isothiourea     2-Hydroxy-3-iminomethyl benzoic acid, compound with thiourea     (3,4,5-Trimethoxyphenyl)thiourea     3-(4-Chlorophenyl)-1,1-dimethyl-2-thiourea     3-(Adamantane-1-carbonyl)-1,1-diethylthiourea     3-Allyl-1-(3-chlorobenzyl)-1-methyl-2-thiourea     3-Benzoyl-1,1-diallyl-2-thiourea     3-Benzoyl-1,1-dimethylthiourea     3-Benzyl-1,1-dimethyl-2-thiourea     (3-Dimethylaminopropyl)thiourea     (3-Fluorophenyl)thiourea     [3-(Trifluoromethyl)phenyl]thiourea     (4-Ethoxyphenyl)thiourea     (4-Fluorophenyl)thiourea     Acetylthiourea     Ethylene bis(isothiourea)     N-(1,1-Dioxidotetrahydro-3-thienyl)-N′-(2-furoyl)-N-methylthiourea     N′-(1,3-Dimethyl-2,4-dioxo-1,2,3,4-tetrahydro-5-pyrimidinyl)-N,N-dimethylthiourea     N-((1,3-Dioxo-3,4-dihydro-2(1H)-naphthalenylidene)methyl)-N′-octadecylthiourea     N-(1-(4-Br[omo]phenyl)ethylidene)-N′-(4-me[thyl]-6-oxo-1,6-dihydro-2-pyrimidinyl)thiourea     N-(1-Methyl-2-phenylethyl)thiourea     N-(1-Methyl-2-propenyl)-N′-(4-morpholinyl)thiourea     N-(2-((1,1,2,2,3,3,3-Heptafluoropropyl)thio)ph[enyl])-N′-(2-thienylcarbonyl)thiourea     N-(2-((2,4-Dichlorobenzyl)sulfonyl)-2-(2,4-dichlorophenyl)vinyl)thiourea     N-(2,2-Dicyanovinyl)thiourea     N-(2,2-Dimethylpropanoyl)-N′-(2-nitrophenyl)thiourea     N-(2-(2-Oxo-1-pyrrolidinyl)ethyl)-N′-phenylthiourea     N-(2-(3,4-Dimethoxyph[enyl])et[thyl])-N′-((2,4-dioxo-2H-coumarin-3(4H)-ylidene)me[thyl])thiourea     N-(2,3-Dichlorophenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(2,3-Dihydro-1,4-benzodioxin-2-yl-methyl)-N′-(4-methylbenzoyl)thiourea     N-(2,4,6-Trichlorophenyl)thiourea     N-((2,4,6-Trioxotetrahydro-5(2H)-pyrimidinylidene)methyl)thiourea     N-(2,4-Dichlorobenzoyl)-N′-(2-pyridinylmethyl)thiourea     N-(2,4-Dichlorobenzoyl)-N′-(tetrahydro-2-furanylmethyl)thiourea     N-(2,4-Dichlorophenyl)-N′-(2,2,2-trichloro-1-(formylamino)ethyl)thiourea     N-(2,4-Dichlorophenyl)-N′-(2-methylbenzoyl)thiourea     N-(2,4-Difluorophenyl)-N′-(2-methylbenzoyl)thiourea     N-(2,4-Difluorophenyl)-N′-(3-methyl-2-furoyl)thiourea     N-(2,4-Dimethylphenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(2,4-Dimethylphenyl)-N′-(2-methylbenzoyl)thiourea     N-(2,4-Dimethylphenyl)-N′-(3-furoyl)thiourea     N-(2,4-Dimethylphenyl)-N′-(3-methyl-2-furoyl)thiourea     N-(2,4-Dimethylphenyl)-N′-(4-methylbenzoyl)thiourea     N-(2,4-Dimethylphenyl)thiourea     N-((2,4-Dioxo-1,2,3,4-tetrahydro-3-quinolinyl)methyl)-N′-hexylthiourea     N-(2,4-Dioxo-1,2,3,4-tetrahydro-5-pyrimidinyl)-N′-(4-methylbenzoyl)thiourea     N-((2,4-Dioxo-2H-coumarin-N-3(4H)-ylidene)methyl)-N′-octadecylthiourea     N-((2,4-Dioxo-2H-coumarin-N-3(4H)-ylidene)methyl)-N′-phenylthiourea     N-(2,5-Dichlorophenyl)-N′-(2,2,2-trichloro-1-(formylamino)ethyl)thiourea     N-(2,5-Dichlorophenyl)thiourea     N-(2,6-Dime[thyl]ph[enyl])-N′-((2,4-dioxo-1,4-dihydro-3(2H)-quinolinylidene)me[thyl])thiourea     N-(2,6-Dichlorophenyl)-N′-(3-furoyl)thiourea     N-(2,6-Dichlorophenyl)-N′-(5-methyl-2-furoyl)thiourea     N-(2-Benzoyl-3-oxo-3-phenyl-1-propenyl)-N′-(2-tert-butyl-6-ethylphenyl)thiourea     N-(2-(Benzylsulfinyl)-2-phenylvinyl)-N′-(2,4-dimethylphenyl)thiourea     N-(2-(Benzylsulfinyl)-2-phenylvinyl)-N′-(2-tert-butyl-6-ethylphenyl)thiourea     N-(2-(Benzylsulfinyl)-2-phenylvinyl)-N′-phenylthiourea     N-(2-Bromobenzoyl)-N′-(2-furylmethyl)thiourea     N-(2-Chlorobenzoyl)-N′-(5-(3-(2-furyl)acryloyl)-4-me[thyl]-1,3-thiazole-2-yl)thiourea     N-(2-Chlorophenyl)-N′-((6-me[thyl]-2,4-dioxo-2H-pyrane-3(4H)-ylidene)methyl)thiourea     N-(2-Fluorophenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(2-Fluorophenyl)-N′-(3-methyl-2-furoyl)thiourea     N-(2-Fluorophenyl)-N′-(5-methyl-2-furoyl)thiourea     N-(2-Furoyl)-N′-(4-methylphenyl)thiourea     N-(2-Furoyl)-N′-(4-(trifluoromethoxy)phenyl)thiourea     N-(2-me[th]o[xy]benzylidene)-N′-(4-me[thyl]-6-oxo-1,6-dihydro-2-pyrimidinyl)thiourea     N-(2-Methyl-3-furoyl)-N′-(4-(trifluoromethyl)phenyl)thiourea     N-(2-Methylbenzoyl)-N′-(2-pyridinyl)thiourea     N-(2-Methylphenyl)-N′-(3-me[thyl]-5-thioxo-1,5-dihydro-4H-1,2,4-triazole-4-yl)thiourea     N-(3-((1,1,2,2,3,3,3-Heptafluoropropyl)thio)ph[enyl])-N′-(2-thienylcarbonyl)thiourea     N-(3,4-Dic[hloro]benzoyl)-N′-(5-(3-(2-furyl)acryloyl)-4-me[thyl]-1,3-thiazole-2-yl)thiourea     N-(3,4-Dichlorophenyl)-N′-(3-methyl-2-furoyl)thiourea     N-(3,4-Dichlorophenyl)-N′-(5-methyl-2-furoyl)thiourea     N-(3,4-Dihydro-2H-pyrrole-5-yl)-N-phenylthiourea     N-(3,4-Dimethoxybenzylidene)-N′-(4-me[thyl]-6-oxo-1,6-dihydro-2-pyrimidinyl)thiourea     N-(3,4-Dimethylphenyl)thiourea     N-(3,5-Bis(trifluoromethoxy)phenyl)-N′-(3-furoyl)thiourea     N-(3,5-Dibromo-2-pyridinyl)-N′-(2-thienylcarbonyl)thiourea     N-(3,5-Dibromo-2-pyridinyl)-N′-(4-methylbenzoyl)thiourea     N-(3-Acetamidophenyl)thiourea     N-(3-Br[omo]benzoyl)-N′-(5-(3-(3-br[omo]phenyl)acryloyl)-4-me[thyl]-1,3-thiazole-2-yl)thiourea     N-(3-Carboxyphenyl)thiourea     N-(3-((Difluoromethyl)thio)phenyl)-N′-(2-thienylcarbonyl)thiourea     N-(3-Ethoxy-4-HO[sic]-benzylidene)-N′-(4-me[thyl]-6-oxo-1,6-dihydro-2-pyrimidinyl)thiourea     N-(3-Fluorophenyl)thiourea     N-(3-Furoyl)-N′-(4-iodophenyl)thiourea     N-(3-Furoyl)-N′-(4-methoxyphenyl)thiourea     N-(3-Furoyl)-N′-(4-(trifluoromethyl)phenyl)thiourea     N-(3-Hydroxyphenyl)thiourea     N-(3-Methoxyphenyl)thiourea     N-(3-Methoxyphenyl)thiourea     N-(3-Methyl-2-butenoyl)-N′-phenylthiourea     N-(3-Methyl-2-furoyl)-N′-(3-(trifluoromethyl)phenyl)thiourea     N-(3-Methyl-2-furoyl)-N′-(4-methylphenyl)thiourea     N-(3-Methyl-2-furoyl)-N′-(4-(trifluoromethyl)phenyl)thiourea     N-((3-Methyl-5-oxo-1-phenyl-1,5-dihydro-4H-pyrazole-4-ylidene)methyl)thiourea     N-(3-Methyl-5-thioxo-1,5-dihydro-4H-1,2,4-triazole-4-yl)-N′-phenylthiourea     N-(3-Methylphenyl)-N′-(3-me[thyl]-5-thioxo-1,5-dihydro-4H-1,2,4-triazole-4-yl)thiourea     N-(3-Methylphenyl)-N′-(4-methyl-1-piperazinyl)thiourea     N-(3-(Trifluoromethyl)phenyl)-N′-(1,2,2-trimethylpropyl)thiourea     N-(4-(2-Thienyl)-1,3-thiazole-2-yl)thiourea     N-(4-((4-Fluorobenzyl)thio)phenyl)-N′-(4-methoxyphenyl)thiourea     N-(4-(4-Morpholinyl)phenyl)-N′-(2-thienylcarbonyl)thiourea     N-(4-(4-Morpholinyl)phenyl)-N′-(4-nitrobenzoyl)thiourea     N-(4-Acetamidophenyl)thiourea     N-(4-Bromobenzylidene)-N′-(6-me[thyl]-5-oxo-4,5-dihydro-1,2,4-triazine-3-yl)thiourea     N-(4-Bromophenyl)-N′-(3-furoyl)thiourea     N-(4-Carboxyphenyl)thiourea     N-(4-Chlorobenzylidene)-N′-(4-methyl-6-oxo-1,6-dihydro-2-pyrimidinyl)thiourea     N-((4-Chlorophenoxy)acetyl)-N′-(2-nitrophenyl)thiourea     N-(4-Chlorophenyl)-N′-(2,4-dichlorobenzoyl)thiourea     N-(4-Chlorophenyl)-N′-(2-furoyl)thiourea     N-(4-Chlorophenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(4-Chlorophenyl)-N′-(3-methyl-2-furoyl)thiourea     N-(4-((Difluoromethyl)thio)phenyl)-N′-(2-thienylcarbonyl)thiourea     N-(4-((Difluoromethyl)thio)phenyl)-N′-(phenylacetyl)thiourea     N-(4-Ethoxyphenyl)-N′-(4-methyl-1-piperazinyl)thiourea     N-(4-Ethoxyphenyl)thiourea     N-(4-Fluorophenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(4-Fluorophenyl)-N′-(3-methyl-2-furoyl)thiourea     N-(4-Fluorophenyl)-N′-(4-methylbenzoyl)thiourea     N-(4-Fluorophenyl)-N′-(5-methyl-2-furoyl)thiourea     N-(4-Fluorophenyl)-N′-(phenyl(((phenylsulfonyl)methyl)imino)methyl)thiourea     N-(4-Fluorophenyl)thiourea     N-(4-Hydroxyphenyl)thiourea     N-(4-Iodophenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(4-Me[thyl]-6-oxo-1,6-dihydro-2-pyrimidinyl)-N′-(1-(4-nitroph[enyl])ethylidene)thiourea     N-(4-Methoxybenzylidene)-N′-(4-methyl-6-oxo-1,6-dihydro-2-pyrimidinyl)thiourea     N-(4-Methoxybenzylidene)-N′-(6-me[thyl]-5-oxo-4,5-dihydro-1,2,4-triazine-3-yl)thiourea     N-(4-Methoxyphenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(4-Methoxyphenyl)-N′-(3-me[thyl]-5-thioxo-1,5-dihydro-4H-1,2,4-triazole-4-yl)thiourea     N-(4-Methoxyphenyl)thiourea     N-(4-Methyl-5-(3-(2-methylphenyl)acryloyl)-1,3-thiazole-2-yl)thiourea     N-(4-Methyl-5-(3-(3-nitrophenyl)acryloyl)-1,3-thiazole-2-yl)thiourea     N-(4-Methyl-6-oxo-1,6-dihydro-2-pyrimidinyl)-N′-(2-nitrobenzylidene)thiourea     N-(4-Methylbenzoyl)-N′-(4-(1-piperidinyl)phenyl)thiourea     N-(4-Methylphenyl)-N′-(phenyl(((phenylsulfonyl)methyl)imino)methyl)thiourea     N-(4-Methylphenyl)thiourea     N-(4-Nitrobenzoyl)-N′-(1,3-thiazole-2-yl)thiourea     N-(4-Nitrobenzoyl)-N′-(4-nitrophenyl)thiourea     N-(4-Sulfamoyl)phenyl)thiourea     N-(4-tert-Butylphenyl)-N′-(2-methyl-3-furoyl)thiourea     N-(4-tert-Butylphenyl)-N′-(2-methylbenzoyl)thiourea     N-(4-tert-Butylphenyl)-N′-(2-thienylcarbonyl)thiourea     N-(4-tert-Butylphenyl)-N′-(3-furoyl)thiourea     N-(4-tert-Butylphenyl)-N′-(3-methyl-2-furoyl)thiourea     N-(5-(2,4-Dichlorophenyl)-1,3,4-oxadiazole-2-yl)thiourea     N-(5-(3-(2,4-Dichlorophenyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)thiourea     N-(5-(3-(2-Furyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)-N′-hexanoylthiourea     N-(5-(3-(2-Furyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)-N′-palmritoylthiourea     N-(5-(3-(2-Furyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)-N′-propionylthiourea     N-(5-(3-(2-HO[sic]-ph[enyl])acryloyl)-4-me[thyl]-1,3-thiazole-2-yl)-N′-(4-nitrobenzoyl)thiourea     N-(5-(3-(3,4-Dimethoxyphenyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)thiourea     N-(5-(3-(3-Bromophenyl)acryloyl)-4-me[thyl]-1,3-thiazole-2-yl)-N′-isobutyrylthiourea     N-(5-(3-(3-Bromophenyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)-N′-propionylthiourea     N-(5-(3-(4-Chlorophenyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)thiourea     N-(5-(3-(4-Methoxyphenyl)acryloyl)-4-methyl-1,3-thiazole-2-yl)thiourea     N-(5-(4-Methylphenyl)-1,3,4-oxadiazole-2-yl)thiourea     N-(5-Bromo-2-methoxybenzyl)-N-(4-isopropylphenyl)-N′-phenylthiourea     N-(5-Methyl-2-furoyl)-N′-(2-(trifluoromethyl)phenyl)thiourea     N-(5-(Phenoxymethyl)-1,3,4-oxadiazole-2-yl)thiourea     N-(6-(1,3-Dioxo-1,3-dihydro-2H-isoindole-2-yl)hexanoyl)-N′-(2-me[th]o[xy]phenyl)thiourea     N-((6-Methyl-2,4-dioxo-2H-pyrane-3(4H)-ylidene) methyl)-N′-octadecylthiourea     N-((6-Methyl-2,4-dioxo-2H-pyrane-3(4H)-ylidene)methyl)-N′-phenylthiourea     N-((6-Methyl-2,4-dioxo-2H-pyrane-3(4H)-ylidene)methyl)thiourea     N-(9-Anthrylmethyl)-N′-benzoyl-N-methylthiourea     N-Allyl-N′-((2,4-dioxo-1,2,3,4-tetrahydro-3-quinolinyl)methyl)thiourea     N-Allyl-N′-((2,4-dioxo-2H-coumarin-N-3(4H)-ylidene)methyl)thiourea     N-Allyl-N′-(4-methyl-1-piperazinyl)thiourea     N-Allylthiourea(2)     N-Benzoyl-N′-(1-naphthyl)thiourea     N-Benzoyl-N′-(2-nitrophenyl)thiourea     N-Benzoyl-N′-(3-methylphenyl)thiourea     N-Benzoyl-N′-(3-pyridinyl)thiourea     N-benzoyl-N′-(4-chlorophenyl)thiourea     N-Benzoyl-N′-(4-methyl-6-oxo-1,6-dihydro-2-pyrimidinyl)thiourea     N′-Benzoyl-N,N-diethylthiourea     N′-Benzoyl-N,N-dihexylthiourea     N′-Benzoyl-N,N-diisobutylthiourea     N-Benzyl-N′-((1,3-dioxo-1,3-dihydro-2H-indene-2-ylidene)methyl)thiourea     N-Benzyl-N′-(1,3-thiazole-2-yl)thiourea     N-Benzyl-N′-(2-pyridinyl)thiourea     N-Benzyl-N′-(3-(4-br[omo]ph[enyl])-5-thioxo-1,5-dihydro-4H-1,2,4-triazole-4-yl)thiourea     N-Benzyl-N′-(phenyl(phenylimino)methyl)thiourea     N-Boc-thiourea     N-Butyl-N′-((2,4-dioxo-1,4-dihydro-3(2H)-quinolinylidene)methyl)thiourea     N-Cyclohexyl-N′-(1-phenylethyl)thiourea     N′-Cyclohexyl-N,N-diisobutylthiourea     N-Dansyl-N′-ethylthiourea     N-Decyl-N′-(2-hydroxyethyl)thiourea     N-Ethyl-N′-(3-methyl-2-butenoyl)-N-phenylthiourea     N-Ethylthiourea (2)     N-Hexanoyl-N′-(3-pyridinylmethyl)thiourea     N-Methallyl-N′-methylthiourea     N-Methylthiourea (2)     N,N-Bis(2-cyanoethyl)-N′-hexylthiourea     N,N′-Bis(4-ethoxyphenyl)thiourea     N,N′-Di-boc-S-methylisothiourea     N,N′-Di-(tert-butoxycarbonyl)thiourea     N,N′-Dibutylthiourea(2)     N,N′-Diethylthiourea     N,N′-Dimethylthiourea     N,N′-Diphenylthiourea     N,N′-Diphenylthiourea     N′-Octadecylfluorescein-5-thiourea     N-Phenyl-N′-(phenyl(phenylimino)methyl)thiourea     N-Phenyl-N′-(tetrahydro-2-furanylmethyl)thiourea     N-Phenylthiourea     N-Phenylthiourea     N-(tert-Butyl)-N′-(3-(trifluoromethyl)phenyl)thiourea     (Phenylphenyliminomethyl)thiourea     Propylthiourea     S-[(2-Guanidino-4-thiazoyl)methyl]isothiourea     S-Benzylisothiourea     S-Ethylisothiourea     S-Isopropylisothiourea     S-Methyl-N-(4-toluenesulfonyl)isothiourea     S-Methylisothiourea     Tetramethylthiourea     Thiourea     Toluene-4-sulfonic acid, 2-(2-(1-oxypyridine-2-yl)ethyl)isothiourea     1,3-Bis-(benzyloxycarbonyl)-2-methyl-2-thiopseudourea     1,3-Bis-(tert-butoxycarbonyl)-2-methyl-2-thiopseudourea     2-Benzyl-2-thiopseudourea     2-Ethyl-2-thiopseudourea     2-Imidazolidinethione     2-Imino-4-thiobiuret     (Amidinothio)acetic acid     Formamidine sulfinic acid     S-(2-Aminoethyl)isothiouronium bromide    
 
         [0644]     Primarily considered as copper compounds are salts and complexes of copper such as copper benzoate, copper di(methacrylate), copper acetylacetonate, or copper naphthenate, for example.  
         [0645]     As monomers without an acid function, in addition to the vinyl and vinylcyclopropane monomers primarily acrylates and methacrylates are considered.  
         [0646]     Monofunctional or crosslinking 1  (meth)acrylates may be monofunctional or polyfunctional (meth)acrylates which may be used individually or in mixtures. Examples of these compounds include methyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, butanediol dimethacrylate, hexanediol dimethacrylate, decanediol dimethacrylate, dodecanediol dimethacrylate, bisphenol-A-dimethacrylate, trimethylolpropane trimethacrylate, ethoxylated bisphenol-A-dimethacrylate, but also bis-GMA (2,2-bis-4-(3-methacryloxy-2-hydroxypropyl)phenylpropane) and the reaction products of isocyanates, in particular di- and/or triisocyanates and methacrylates containing OH groups, and the corresponding acrylates of all the above compounds. Examples of reaction products of isocyanates are the reaction products of 1 mol hexamethylene diisocyanate with 2 mol 2-hydroxyethyl methacrylate, of 1 mol (tri(6-isocyanatohexyl)biuret with 3 mol hydroxyethyl methacrylate, and of 1 mol trimethylhexamethylene diisocyanate with 2 mol hydroxyethyl methacrylate, which are also referred to as urethane dimethacrylates. Suitable monomers in each case are the monomers themselves, prepolymers prepared from same, and mixtures thereof.  Crosslinking meth/acrylates by their nature are compounds containing 2 or more methacrylate groups in the monomer.    
         [0647]     Examples of preferred crosslinker monomers are 2,2-bis-4-(3-methacryloxy-2-hydroxypropyl)phenylpropane) (bis-GMA), i.e., the reaction product of glycidyl methacrylate and bisphenol-A (containing OH groups), and 7,7,9-trimethyl-4,13-dioxo-3,14-dioxa-5,12-diazahexadecane-1,16-diyl-dimethacrylate (UDMA), i.e., the urethane dimethacrylate resulting from 2 mol 2-hydroxyethyl methacrylate (HEMA) and 1 mol 2-2,4-trimethylhexamethylene diisocyanate (containing urethane groups). Also preferred as crosslinker monomers are reaction products of glycidyl methacrylate with other bisphenols such as bisphenol-B (2,2′-bis-(4-hydroxyphenyl)butane), bisphenol-F (2,2′-methylenediphenol), or 4,4′-dihydroxydiphenyl, for example, and reaction products of 2 mol HEMA or 2-hydroxypropyl(meth)acrylate with in particular 1 mol of known diisocyanates such as hexamethylene diisocyanate, m-xylylene diisocyanate, or toluylene diisocyanate, for example.  
         [0000]     Test Descriptions/Examples:  
         [0648]     The two components, referred to below as base and catalyst component (B and C, respectively), were prepared according to a general production specification. For this purpose, the monomers were first blended into a homogeneous mixture. The initiator components were then added, and were dissolved by intensive stirring with a magnetic stirrer.  
         [0649]     The special properties of the two-component initiator system according to the invention were investigated in greater detail for the following compositions. The components B1 in combination with C1 and C2 represent the reference system.  
                                                                             Base components                B1   Bis-GMA   20.580               TEGDMA   8.820               DBPO   0.600           B2   Bis-GMA   20.790               TEGDMA   8.910               CHP   0.300           B9   Bis-GMA   20.37               TEGDMA   8.73               CHP   0.900           B10   Bis-GMA   19.347               TEGDMA   8.291               Acrylic acid   1.455               CHP   0.907           B122   Bis-GMA   17.64               TEGDMA   7.56               CHP   0.300 (1.00%)               4-Meta    4.500 (15.00%)           B123   Bis-GMA   20.37               TEGDMA   8.73               CHP   0.300 (1.00%)               Phosphoric acid ester   0.600 (2.00%)           B124   Bis-GMA   19.74               TEGDMA   8.46               CHP   0.300 (1.00%)               Phosphoric acid ester   1.500 (5.00%)            Catalyst components                C1   Bis-GMA   20.895               TEGDMA   8.955               DMPT   0.150           C2   Bis-GMA   20.895               TEGDMA   8.955               DHEPT   0.150           C3   Bis-GMA   20.790               TEGDMA   8.910               ATH   0.300           C3.1   Bis-GMA   20.51               TEGDMA   8.79               ATH   0.900           C3.4   Bis-GMA   20.769               TEGDMA   8.901               ATH   0.300               Cu(acac) 2     0.030           C3.5   Bis-GMA   20.348               TEGDMA   8.721               ATH   0.901               Cu(acac) 2     0.029           C15   Bis-GMA   20.348               TEGDMA   8.721               ATH   0.901               Copper (II) naphthenate   0.029           C121   Bis-GMA   20.782               TEGDMA   8.906               ATH   0.300 (1.00%)               Cu(ac) 2     0.012 (0.04%)           C122   Bis-GMA   17.632               TEGDMA   7.556               4-Meta     4.5 (15.00%)               ATH   0.300 (1.00%)               Cu(ac)2   0.012 (0.04%)           C123   Bis-GMA   20.362               TEGDMA   8.726               Sipomer PAM100    0.6 (2.00%)               ATH   0.300 (1.00%)               Cu(ac) 2     0.012 (0.04%)           C124   Bis-GMA   19.732               TEGDMA   8.456               Sipomer PAM100    1.5 (5.00%)               ATH   0.300 (1.00%)               Cu(ac) 2     0.012 (0.04%)                      
 
         [0650]     By introducing conventional fillers into the activated monomer resin mixtures, one skilled in the art may produce composites for various dental applications.  
         [0651]     Suitable in particular as fillers are quartz powder and glass ceramic powder, aluminum oxides, and/or silicon oxides. Examples of particularly preferred fillers are glass powders such as barium glass, barium silicate glass, lithium, or aluminum silicate glass powders, and fine-particle silicic acids such as pyrogenic or precipitated silicic acids.  
         [0000]     Testing of Gel Times  
         [0652]     To determine processing times, both components were intensively mixed in a 1:1 ratio. The time required for the gel point to appear is referred to as the gel time, which may be observed for adjusting the maximum processing time. However, sensory perception is subject to individual fluctuation ranges which also depend on the curing characteristics of the system.  
         [0653]     As an additional method for determining the initiation characteristics, the heat of reaction was calorimetrically recorded. The initial temperature increase was specified as the relevant measurement point.  
         [0654]     The measurements showed a reliably adjustable processing time as a function of the copper content in the preparations. The variation range of the activity of the initiator system extends from extremely short inhibition times of &lt;10 s for higher copper content (approximately 0.1%) to very long inhibition times, or even results in failure of polymerization in the absence of the copper compound.  
         [0000]     Testing of Storage Stability  
         [0655]     The individual components were placed in long-term storage at a temperature of 50° C. The change in processing times was documented over a maximum period of 5 months. The samples were tested using the second component, which likewise was stored at 50° C. or at room temperature (RT).  
         [0656]     Whereas the base component of the conventional dibenzoyl peroxide-amine initiator system had spontaneously cured after 10 days, the components of the system according to the invention were still usable after 5 months. The curing was also reliably carried out in the presence of adhesive monomers under acidic conditions. The strong catalytic effect of the copper content on the activity of the initiator system was very evident in the tests. As a function of the proportion of a soluble copper compound, it was possible to demonstrably adjust much shorter processing times or to reduce the concentration of the redox partners. Both possibilities are particularly advantageous for use in dental materials, or synthetic materials for medical use, which require very brief processing times and the least possible toxicological potential.  
                                                                                 Reference system: dibenzoyl peroxide-amine                   Reference - Storage of the peroxide component at 50° C.                        B1   1% DBPO    0 days    50 s                    5 days    40 s                   10 days   polymerized                        Reference - Storage of the amine component at 50° C.                            B1                       1% DBPO                       C1   0.5% DMPT    0 months    50 s                    3 months    95 s                    5 months   —           C2   0.5% DHEPT    0 months   380 s                    3 months   —                    5 months   420 s                      
 
         [0657]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
               
             
               
             
               
               
               
               
               
             
           
               
                   
               
               
                   
               
               
                 System: cumene hydroperoxide-acetylthiourea derivative 
               
               
                   
               
             
             
               
                 Storage of both components at 50° C. 
               
             
          
           
               
                   
                   
                   
                   
                 C3 
                 C3.1 
               
               
                   
                   
                   
                   
                 1% ATH 
                 3% ATH 
               
               
                   
                   
               
               
                   
                 B9 
                 3% CHP 
                 0 months 
                 480 s 
                 280 s 
               
               
                   
                   
                   
                 3 months 
                 390 s 
                 120 s 
               
               
                   
                   
                   
                 5 months 
                 200 s 
               
               
                   
                 B10 
                 3% CHP 
                 0 months 
                 210 s 
                  95 s 
               
               
                   
                   
                 5% acrylic acid 
                 5 months 
                 225 s 
                 230 s 
               
               
                   
                   
               
             
          
           
               
                 Storage of both components at 50° C., with addition of copper 
               
             
          
           
               
                   
                   
                   
                   
                 B2 
               
               
                   
                   
                   
                   
                 1% CHP 
               
               
                   
                   
               
               
                   
                 C121 
                 1% ATH 
                 0 months 
                  45 s 
               
               
                   
                   
                 0.04% Cu(acac) 2   
                 1 month 
                 — 
               
               
                   
                   
                   
                 3 months 
                 235 s 
               
               
                   
                 C3.5 
                 1% ATH 
                 0 months 
                  35 s 
               
               
                   
                   
                 0.1% Cu(acac) 2   
                 1 month 
                  70 s 
               
               
                   
                   
                   
                 3 months 
                 345 s 
               
               
                   
                 C3.4 
                 3% ATH 
                 0 months 
                  40 s 
               
               
                   
                   
                 0.1% Cu(acac) 2   
                 1 month 
                  80 s 
               
               
                   
                   
                   
                 3 months 
                 200 s 
               
               
                   
                   
               
             
          
           
               
                 Storage of ATH components at 50° C., with adhesive monomer 
               
               
                 and addition of copper 
               
             
          
           
               
                   
                   
                   
                   
                 B2 
               
               
                   
                   
                   
                   
                 1% CHP 
               
               
                   
                   
               
               
                   
                 C121 
                 1% ATH, 0.04% 
                 0 months 
                  45 s 
               
               
                   
                   
                 Cu(acac) 2   
                 3 months 
                  85 s 
               
               
                   
                 C122 
                 1% ATH, 0.04% 
                 0 months 
                 110 s 
               
               
                   
                   
                 Cu(acac) 2   
                 3 months 
                 160 s 
               
               
                   
                   
                 15% 4-META 
               
               
                   
                 C123 
                 1% ATH, 0.04% 
                 0 months 
                  50 s 
               
               
                   
                   
                 Cu(acac) 2   
                 3 months 
                  70 s 
               
               
                   
                   
                 2% phosphoric acid ester 
               
               
                   
                 C124 
                 1% ATH, 0.04% 
                 0 months 
                  50 s 
               
               
                   
                   
                 Cu(acac) 2   
                 3 months 
                  70 s 
               
               
                   
                   
                 5% phosphoric acid ester 
               
               
                   
                   
               
             
          
         
       
     
         [0658]    
       
         
               
             
               
               
             
               
               
               
               
               
             
           
               
                   
               
               
                   
               
               
                 Dependence of the inhibition time on copper content 
               
               
                 Adjustment of the processing time to the copper content 
               
             
          
           
               
                   
                 B2 
               
               
                   
                 1% CHP 
               
               
                   
                   
               
             
          
           
               
                   
                 C3 
                 1% ATH 
                 0.00% Cu(acac) 2   
                 No polymerization 
               
               
                   
                   
                   
                 0.01% Cu(acac) 2   
                 135 s  
               
               
                   
                   
                   
                 0.02% Cu(acac) 2   
                 75 s 
               
               
                   
                 C121 
                   
                 0.04% Cu(acac) 2   
                 45 s 
               
               
                   
                   
                   
                 0.06% Cu(acac) 2   
                 40 s 
               
               
                   
                 C3.5 
                   
                 0.10% Cu(acac) 2   
                 35 s 
               
               
                   
                   
               
             
          
         
       
     
         [0659]    
               
       
         
               
             
               
               
             
               
               
               
               
               
             
           
               
                   
               
               
                   
               
               
                 Effectiveness of various copper salts 
               
             
          
           
               
                   
                 B2 
               
               
                   
                 1% CHP 
               
               
                   
                   
               
             
          
           
               
                   
                 C3.5 
                 1% ATH 
                 0.10% copper (II) 
                 35 s 
               
               
                   
                   
                   
                 acetonylacetonate 
               
               
                   
                 C15 
                   
                 0.10% copper (II) naphthenate 
                 55 s 
               
               
                   
                   
               
               
                   
                   Coloration of polymers as a function of the copper content    
               
             
          
         
       
     
         [0660]     The color of polymerized (meth)acrylates is affected by the content of copper ions, which by their nature are colored. The relationship between the intrinsic coloration of the polymer and the proportion of the copper compound was determined by color measurements on test specimens. Color stability was of particular importance.  
         [0661]     For the determination, test specimens 1 mm in thickness were produced, and after 48-hour storage were measured. The CIELab values of the transparent polymer layers in front of a white background were recorded. The color stability was monitored after 7 days at a temperature of 40° C. No change in color of the layers was observed.  
         [0662]     Even after longer storage there was no detectable change in color. Therefore, the initiator system according to the invention together with a copper compound also completely meets the esthetic demands placed on a dental material.