Polyhydantoin and production process thereof
United States Patent [191 Okada et al.  
 [451 Apr. s, 1975 POLYHYDANTOIN AND PRODUCTION PROCESS THEREOF [75] inventors: Shin-Ichi Okada; Masahiro Suzuki;  
 Akio Omi, all of Hitachi, Japan [73] Assignee: Hitachi Cable, Ltd., Tokyo, Japan [22] Filed: July 24, 1973 [2i] Appl. No.: 382,189  
  52 us. Cl... 260/77.5 c; 260/775 CH; 260/3095 s 1 im. Cl C08g 22/00 [58] Field of Search..... 260/775 c, 77.5 CH, 309.5  
 [56] References Cited UNITED STATES PATENTS 3,684,774 8/]972 Merten et al. 260/775 C Primary Examiner?M. J. Welsh Attorney, Agent, or FirmCraig &amp; Antonelli [57] ABSTRACT A novel polyhyda&#39;ntoin is produced by heating at a temperature of l00 to 350C. at least one compound represented by the formula, 1  
 R&#39;OOCHN-:--R--NHCH COOR&#34; wherein R is a divalent aliphatic, cycloaliphatic, or aromatic residue, and R and R&#34; are independently hydrogen or monovalent aliphatic, cycloaliphatic, or aromatic residues. The said polyhydantoin is excellent in thermal resistance, electrical strengths, mechanical strengths, and chemical resistance, and may be used as a material for molding, lamination, impregnation, and adhering.  
 13 Claims, No Drawings POLYHYDANTOIN AND PRODUCTION PROCESS THEREOF This invention relates to a heat-resistant polymer having in its molecule a hydantoin ring, and to a process for producing the same.  
  As such a polymer, there has generally been known a copolymer obtained from a diglycine derivative and a diisocyanate. Since the process for the preparation of such a copolymer involves formation of a prepolymer by addition reaction of a diisocyanate to a diglicine derivative and cyclization which takes place subsequently to the addition reaction to form a hydantion ring. Thus, copolymerization reaction proceeds in said process, and hence, the mole ratio between the diglycine derivative and the diisocyanate plays an important role. These two reactants should always be maintained in an equimolar relation to each other, and if such a molar relation is disturbed, the molecular weight of the reaction product becomes insufficient corresponding to the degree of disturbance, thus leading to marked deterioration in the favorable thermal resistance, tensile strength, abrasion resistance, and chemical resistance, which this type of polymer has otherwise.  
  Such a phenomenon raises a serious trouble in securing the quality of polyhydantoin and in promoting practical application thereof. Moreover, a process involving adjustment of the mole ratio of reactants, which is a troublesome procedure in process control, is obviously disadvantageous from an industrial viewpoint, as compared with an alternative process which does not need such an adjustment.  
  This invention provides a novel polyhydantoin consisting essentially of homopolymer which has been freed from the aforesaid disadvantages.  
  An object of this invention is to provide a polyhydantoin of an entirely new modecular structure, and another object is to provide an advantageous process for producing a polyhydantoin based on a new idea. A further object of this invention is to provide an advantageous process for producing a polyhydantoin, wherein adjustment of the mole ratio of reactant materials is not needed at all.  
  According to this invention, there is provided a polyhydantoin having the general formula wherein R is a divalent aliphatic, cycloaliphatic, or aromatic residue, and n is an integer of 30 or more, preferably 30 to 8,000. This invention also provides a process for producing the said polyhydantoin, which comprises polycondensation of at least one compound having the general formula R&#39;OOCHNRNHCH- -COOR&#34; (I), wherein R has the same meaning as defined above, and R and R&#34; are independently hydrogen or monovalent aliphatic, cycloaliphatic, or aromatic residues.  
  The compounds represented by the formula (I) can be further expressed by the following more specific general formulas, though not restricted thereto:  
  I n R 000 HN Q NH CH2 COOR (where x is CH C0, S, S0 or a single linkage);  
 R&#39;OO-C-HN @@NH-CH2-COOR&#34; and R &#39;OOC-HN CH Q NH-CH -COOR (where m is 1 to 10).  
  Examples of these compounds to be used in this invention are as shown below.  
  N-Carbomethoxy-N&#39;-carboxymethylbenzidine, N- carboethoxy-N-carbomethoxymethylbenzidine, N- carboethoxy-N-carboethoxymethylbenzidine, N-  
 carbomethoxy-N-carbomethoxymethyl-4,4 diaminodiphenyl ether, N-carboethoxy-N- carboethoxymethyl-4,4&#39;-diaminodiphenyl ether, N- carbomethyoxy-N&#39;-carbomethoxymethyl-4,4&#39;- diaminodiphenylmethane, N-carbomethoxy-N- carboethoxymethyl-4,4-diaminodiphenylmethane, N- carboethoxy-N&#39;-carboethoxymethyl-4,4&#39;- diaminodiphenylmethane, N-carboethoxymethyl-4,4&#39;- diaminodiphenylmethane, N-carboethoxy-N carbopropoxymethyl-4,4&#39;-diaminodiphenylmethane, N-carbocyclohexoxy-N &#39;-carboethoxymethyl-4,4 diaminodiphenylmethane, N-carbophenoxy-N- carboethoxymethyl-4,4&#39;-diaminodiphenylmethane, N- carbomethoxy-N-carboethoxymethyl-4,4&#39;- diaminodiphenyl sulfone, N-carboethoxy-N- carboethoxymethyl-4,4&#39;-diaminodiphenyl sulfone, N- carbomethoxy-N -carboethoxymethyl-4,4 diaminobenzophenone, N-carboethoxy-N&#39;- carboethoxymethyl-4,4-diaminobenzophenone, N- carboethoxy-N-&#39;-carbophenoxymethyl-4,4&#39;- diaminobenzophenone, N-carbomethoxy-N carboethoxymethyl-o-toluidine, N-carboethoxy-N carboethoxymethyl-o-toluidine, N-carbomethoxy-N- carboethoxy-4,4-diaminodiphenyl sulfide, N- carboethoxy-N-carboethoxymethyl-4,4&#39;- diaminodiphenyl sulfide, N-carbomethoxy-N&#39;- carbomethoxymethyl-p-phenylenediamine, N- carbomethoxy-N-carboethoxymethyl-pphenylenediamine, N-carboethoxy-N&#39;- carbomethoxymethyl-m-phenylenediamine, N- carbomethoxy-N -carbomethoxymethyl-mphenylenediamine, N-carboethoxy-N- carboethoxymethyl-m-phenylenediamine, N- carbophenoxy-N -carboethoxymethyl-mphenylenediamine, N-carbophenoxy-N- carbophenoxymethyl-m-phenylenediamine, N- carboethoxy-N-carbopropoxymethyl-mphenylenediamine, N-carboxy-N&#39;-carbobutoxymethylm-phenylenediamine, N-carboxy-N&#39;-carboxymethylm-phenylenediamine N-carboethoxy-N carboxymethyll ,5 -diaminonaphthalene, N- carbomethoxy-N &#39;-carboethoxymethyl-l ,5- diaminonaphthalene, N-carboethoxy-N carboethoxymethyl-l ,5 -diaminonaphthalene, N- carboethoxy-N&#39;-carbobutoxymethyl-l ,5- diaminonaphthalene, N-carboxy-N-carboxymethylethylenediamine, N-carbomethyoxy-N&#39;- carboethoxymethyl-l ,3-diaminopropane, N-  
 carboethoxy-N&#39;-carboethoxymethyl-l,4- The above reactions are based on the thermal splitdiaminobutane, N-carboethoxy-N&#39;-carboethoxy-1,6- ting-off of ROH, the formation of NCO radical resultdiaminohexane, N-carbophenoxy-N-carboethoxy-l,6- ing therefrom, and the addition reaction of the NCO diaminohexane, N-carboethoxy-N-carboethoxy-l,4- radical to NH radical. The formation of a polymer of diaminocyclohexane, N-carboethoxy-N&#39;- 5 the formula (II) and the subsequent cyclization to hycarboxymethyl-l ,4-diaminocyclohexane, N- dantoin ring (III) proceed with comparatively high efficarbomethoxy-N&#39;-carboethoxymethyl-1,8- ciency. On the other hand, when R is an aliphatic or diaminooctane, N-carboethoxy-N-carboethoxymetha cycloaliphatic residue, the splitting reaction to form yl-l,8-diaminooctane, N-carboethoxy-N&#39;- a NCO radical takes place with great difficulty so that carboxymethyl-l ,8-diaminooctane, etc. These comit becomes desirable to call for the assistance of a catapounds may be used alone or in admixture of two or lyst. As such a catalyst, there may be used those commore. pounds which have been known as aminolysis catalysts, Synthesis of these compounds comprises the followsuch as, for example, lead monoxide, magnesium oxide, ing steps in the case of, for example, N-carbomethoxyantimony trioxide, and other metallic oxides, tetrabutyl N&#39;-carbomethoxymethyl-4,4&#39;- titanate and other organometallic compounds. In this diaminodiphenylmethane: Af first, 1 mole of 4,4- case, the type of reaction becomes as follows:  
 CH lD-j-O-R&#34;; It H 0 C=O -R-&#39; ;H Catalyst l l r. &#39;-l R-N N H R&#39;-O-C N- n ll o 3 diaminodiphenylmethane is added to water containing The presence of a catalyst promotes splitting-off of a hydrogen halide acceptor such as calcium carbonate; R&#39;OI-I and R&#34;OH, and the formation of a polymer proto the resulting mixture is added 1 mole of halogenated ceeds efficiently. methylacetate in small portions with stirring and the In either case, the formation of a polymer may be mixture is allowed to react with stirring at 50C. for 4 recognized by an increase in viscosity of the reaction hours; to the reaction mixture is then added 1 mole of system, and the degree of formation may be confirmed halogenated methyl carbonate in small portions with by taking, for example, reduced specific viscosity as a stirring and allowed to react with stirring for a further measure.  
 3 hours; the reaction product is washed with water and The polyhydantoin of this invention is characterized then recrystallized from methanol. by being a homopolymer having a recurring unit of the Although the method for synthesizing the aboveformula noted compounds is, of course, not limited to that mentioned above as an example, yet the above-mentioned H C (3:0 method is applicable to the synthesis of other compounds, in which cases diamines, halogenated acetate 40 -RN N- ester compounds, and halogenated carbonate ester compounds are properly selected in accordance with the molecular structure of the desired final compounds.  
  The polycondensation reaction to form a polymer is 7 usually conducted in an organic solvent such as m- This originates from the molecular structure of the cresol, phenol, xylenol, N,N-dimethylformamide, N,N- starting material represented by the formula (I). It is a dimethylacetamide, N-methyl-2-pyrrolidone, or the great advantage that since the homopolymer is formed like, and, if necessary, a diluent such as benzene, toluby condensation reaction of a single starting material,  
 ene, ethanol, propanol, butanol, furfural, methyl Cellothe molecular weight always becomes large and there solve, ethyl Cellosolve, or the like.  
  The temperature of polycondensation is preferably as results from an unbalance in mole ratio between the to 350C, more preferably to 250C. reactants in the case where the polymer is formed by The reaction is desirably conducted under varying the reaction between two components as mentioned in conditions according to the type of R in the formula 55 the introductory part hereof.  
 (I). Generally speaking, when R is an aromatic residue The invention is further explained below in detail such as phenyl radical, the reaction proceeds according with reference to examples which are by way of illustrato the following scheme: tion and not by way of limitation.  
 Polyeondensation 2 (II) l-N-C-WH- l (III) is no formation of such a low molecular weight polymer- EXAMPLE 1 In a 2-liter flask were placed 374.4 g of N- carboethoxy-N&#39;-carboethoxymethyl-4,4&#39;- diaminodiphenylmethane, 280.0 g of commercial grade m-cresol, and 0.4 g of lead oxide. The contents of the flask was heated with stirring under a stream of nitrogen and the temperature was elevated to 190C. over a period of about 2 hours. While the temperature was being elevated, distillation of the ethanol formed by the reaction began to be observable at about 180C. When heating was continued with stirring at 190C. for about 6 hours, about 80% of the theoretical amount of ethanol was distilled and the viscosity of the contents of flask was increased.  
  After an additional amount of 140 g of m-cresol was added and the temperature was elevated to 195C., the reaction was continued for about 4 hours, after which the flask contents became a viscous clear liquid. At this point, about 330 g of m-cresol was poured into the flask to terminate the reaction. The flask contents were left standing to cool. I  
  A portion of the reaction solution was added to a large volume of methanol to precipitate a yellowish white polymer. The polymer was tested in m-cresol for the reduced specific viscosity, nsp/c (c=0.5 g/dl), and found to be 0.65 (dl/g).  
 EXAMPLE 2 Following the procedure of Example 1, formation of a polymer was carried out by use of 376.4 g of N- carboethoxy-N -carboethoxymethyl-4,4 diaminodiphenyl ether, 285.0 g of m-cresol, and 0.3 g of lead monoxide. The reduced specific viscosity of the polymer was 0.73 (dl/g) as measured under the same conditions as in Example 1.  
 EXAMPLE 3 Following the procedure of Example 1, formation of a polymer was carried out by use of 260.4 g of N- carbomethoxy-N&#39;-carboethoxymethyl-mphenylenediamine, 360.2 g of N-carboethoxy-N&#39;- carboethoxymethylbenzidine, 436.2 g of m-cresol, and 0.6 g of lead monoxide. The reduced specific viscosity of the resulting polymer was 0.75 (dl/g).  
 EXAMPLE 4 In a 2-liter flask were placed 423.1 g of N- carbophenoxy-N&#39;-carboethoxymethyl-4,4&#39;- diaminodiphenylmethane and 296.5 g of m-cresol. The mixture was heated with stirring while passing a stream of nitrogen, and the temperature was elevated to 200C. over a period of 2 hours. The reaction was continued for hours while removing the phenol and methanol which were formed.  
  To the contents of flask, which had been increased in viscosity as a result of reaction, was added 150 g of mcresol. The mixture was maintained at 200C. for a further 5 hours to continue the reaction, and thereafter admixed with 350 g of cold m-cresol to terminate the reaction.  
  The reduced specific viscosity of the resulting polymer was 0.51 (dl/g), as measured under the same conditions as in Example 1.  
 EXAMPLE 5 In a 2-liter flask were charged 328.4 g of N- carbomethoxy-N&#39;-carbomethoxymethyl-4,4&#39;-  
 &#39;diaminodiphenylmethane, 264.0 g of m-cresol and 1.3  
 g of tetrabutyl titanate. The mixture was heated with stirring while passing a stream of nitrogen, and the temperature was elevated to 195C. over a period of 2 hours. The reaction was continued for a further 5 hours while removing the methanol which was by-produced. After completion of the reaction, the reaction mixture was cooled by addition of 528 g of m-cresol. The reduced specific viscosity of the polymer thus obtained was 0.67 (dl/g).  
 EXAMPLE 6 In a 2-liter flask were placed 300.3 g of N- carbomethoxy-N-carboxymethylbenzidine, 250 g of m-cresol, and 1.3 g of tetrabutyl titanate. The reaction system was heated with stirring while passing a stream of nitrogen, and the temperature was elevated to 195C. over a period of about 2 hours. The reaction was continued for a further Shouts while removing the by-produced methanol and water. Then, the temperature of the reaction system was elevated to 200C., allowed to react at this temperature for 5 hours, and thereafter admixed with 500 g of cold m-cresol to terminate the reaction. The reduced specific viscosity of the polymer thus obtained was 0.53 (dl/g).  
 EXAMPLE 7 In a 2-liter flask were placed 406.5 g of N- carbophenoxy-N&#39;-carboethoxymethyl-4,4&#39;- diaminodiphenyl sulfone and 315 g of m-cresol. The mixture was heated with stirring while passing a stream of nitrogen, and the temperature was elevated to 195C. over a period of about 2 hours. The reaction was continued for a further 8 hours while removing the by-product phenol. After completion of the reaction, the reaction mixture was cooled by addition of 630 g of cold m-cresol. The reduced specific viscosity of the polymer thus formed was 0.58 (dl/g).  
 EXAMPLE 8 A polyhydantoin solution was obtained from 326.3 g of N-carbomethoxy-N -carboXymethyl-1 ,5- diaminonapthalene, 248 g of m-cresol, and 1.7 g of dibutyltin dilaurate under the same heating conditions as in Example 6. The amount of m-cresol added in the final step had been 741 g. The reduced specific viscosity of the polymer was 0.69 (dl/g).  
 EXAMPLE 9 In a 2-liter flask were placed 274.3 g of N- carboethoxy-N -carboethoxymethyl- 1 ,6- diaminohexane, 182 g of m-cresol, and 0.5 g of lead monoxide. The mixture was heated with stirring while passing a stream of nitrogen, and the temperature was elevated to C. over a period of about 2 hours. The reaction was continued for a further 3 hours at this temperature and then for 4 hours at C. Thereafter, 420 g of m-cresol was added to terminate the reaction. The reduced specific viscosity of the polymer thus formed was 0.55 (dl/g).  
 EXAMPLE 10 By using 356.4 g of N-carboethoxy-N- carboethoxymethyl-4,4&#39;-diaminobenzophenone, 278 g of m-cresol, and 1.4 g of tetrabutyl titanate. a polyhydantoin solution was obtained under the same heating conditions as in Example 5, the amount of m-cresol added in the final step having been 556 g. the reduced specific viscosity of the polymer thus formed was 0.65 (dl/g).  
 REFERENTIAL EXAMPLE It will be easily understood from the foregoing explanation that the polyhydantoin of this invention is characterized by being obtained from a specific and single reactant material, and consequently characterized by a novel molecular structure of the homopolymer type In a 2-liter flask were placed 250 g (1 mole) of diphenylmethane-4,4&#39;-diisocyanate, 407 g (1.1 moles) of N,- N&#39;-bis(carboethoxymethyl)-4,4- diaminodiphenylmethane and 1,000 g of m-cresol. The mixture was heated with stirring while passing a stream which 15 ehtlrely dlffereht from a conventional p y yof nitrogen, and the temperature was elevated to dahtoih having a molecular Structure of the chpolymel&#39; 180C. over a period of about 2 hours. The reaction yl A is clear from the foregolhg P Q p was continued for a further 18 hours at this tempera- Tables 1 and 2, the p y y of thls lture. After completion of the re i h reaction tion is not only excellent in thermal resistance, electrimixture was cooled by adding 540 g f 1 Th cal strengths, mechanical strengths, and chemical resispolymer obtained in the present Exam le h d a tance, but also free from the defects of the prior art, duced specific viscosity of 0.21 (dl/g). which orginate from fluctuation in the mole ratio of re- In Table 1 are shown characteristics of films obtained 30181&#34; materials, as shown in Referemial p by coating the final solution obtained in each of the on q en ly, i h n come possible to provide above Examples and Referential Example, admixed a novel type of polyhydantoin having always a high mowith 2.8 g of tetrabutyltitanate, on a plate of glass and lecular weight and excellent characteristics without nethen heating at 220C. for minutes. cessitating special consideration nor supervision re- 20 garding troublesome adjustment of the mole ratio.  
 Table 1 Therefore, it is certain that industrial merit of the pres- Example Thickness Tensile Ultimate Tear ent Polyhydantom Is .very great.  
  Strength elongation Strength Being excellent in thermal resistance, electric g/ (g) strengths, mechanical strengths, and chemical resis- 1 0050 940 48.7 20.8 tance, the polyhydantoin of this invention may be used 2 0.050 10.10 46.4 2 as a material for a borad range of applications including 3 0.050 9.00 49.0 21.5 4 0.050 920 47.2 210 various moldings, lamination, impregnation, and adhe 5 0.050 9.80 48.8 21.2 slves- 6 0.050 9.20 45.7 20.1 What is claimed is; L 7 0.050 10.20 47.0 21.8 8 M50 940 452 22A 1. A process for producing a polyhydantoin, which 9 .050 9.70 82.0 23- comprises heating at a temperature of 100 to 350C at Refeigmial O&#39;OSO least one compound represented by the formula R&#39;OO- Example 0.050 3.90 11.2 5.2 CHN-R-Nl-lCH --COOR&#34;, wherein R is a divalent aliphatic, cycloaliphatic, or aromatic residue, and  
 Note: I I I (1) The tensile strength and the ultimate elongation were measured at a tensile R and R are ldependently hydrogen or monovalent SPeed mm/mini al&#39; h atic or aromatic residu s.  
 (2) The tear strength was measured by Elmendorf method at 23C. and 60 7: 1p atlc cycloahph e relative humidity. 2. A process according to claim 1, wherein said compound is represented by the formula In Table 2 are shown characteristics of insulated electric wires manufactured by use of each of the final 40 n solutions in the aforementioned Examples and Refer- R&#39;OOC HN &#39;X&#34; NH-CH2 COOR ential Example. The insulated wire was manufactured by coating the solution admixed with 2.8 g of tetwherein R and R are independently hydrogen or rabutyltitanate on an anneeled copper wire, 1.00 mm monovalent aliphatic, cycloaliphatic, or aromatic resiin diameter, in an ordinary way, and then baking the dues, and X is Cl-l -O, CO, SO coated wire. S, or a single linkage.  
 Table 2 Referen- Examplc No. tial l 2 3 4 5 6 7 8 9 10 Example Thickness of insulating film. mm 0.040 0.040  
  .040 .039 .040 .040 .040 .040 .040 .039 .040 Windahility (wound on own diameter) OK OK OK OK OK OK OK OK OK OK Cracking Dielectric breakdown initial 12.3 11.8 12.0 11.7 12.2 12.0 1.3 12.2 11.8 12.1 8.3 voltagefluisted pair), kV after aging at 10.5 11.0 11.5 9.6 12.0 11.7 1 .0 1.2.2 9.6 11.8 5.5  
  250C-24 hrs. Abrasion resistance (repeating type. 120 98 105 122 108 124 137 84 1 16 41 600 g load). number of strokes Heat shock resistance 250C./1hr. OK OK OK OK OK OK OK OK OK OK Crackin (wound on own diameter) 300C./lhr. OK OK OK OK OK OK OK OK OK OK Cr acking Chemical resistance {ii-50.. sp.gr.1.12 5H 5H 5H 5H 5H 5H 5H 5H 5H 5H H (pencil hardness method) 10 &#39;71 NaOH 5H 5H 5H 5H 5H 5H 5H 5H 5H 5H H Heat softening performance (250C./6hrs.;  
  Good Poor ood ood ood ood ood ood ood ood ood 1 kg load) Cut-through temperature (2 kg load).C. 415 410 430 380 415 420 418 428 326 408 285 Note: Characteristic properties in Table 2 were measured according to NEMA-MW 1000.  
  3. A process according to claim 2, wherein said compound is represented by the formula wherein R and R are independently hydrogen,  
 methyl groups, ethyl groups, or phenyl groups.  
  4. A process according to claim 2, wherein said compound is represented by the formula wherein R and R&#34; are independently hydrogen, methyl groups, ethyl groups, or phenyl groups.  
  5. A process according to claim 2, wherein said compound is represented by the formula 1 wherein R and R are independently hydrogen, methyl groups, ethyl groups, or phenyl groups.  
  6. A process according to claim 2, wherein said compound is represented by the formula wherein R and R are independently hydrogen, methyl groups, ethyl groups, or phenyl groups.  
  7. A process according to claim 2, wherein said compound is represented by the formula wherein R and R&#34; are independently hydrogen, methyl groups, ethyl groups, or phenyl groups.  
 8. A process according to claim 1, wherein said compound is represented by the formula wherein R and R&#34; are independently hydrogen vor monovalent aliphatic, cycloaliphatic, or aromatic residues.  
  9. A process according to claim 8, wherein said compound is represented by the formula wherein R and R&#34; are independently hydrogen, methyl groups, ethyl groups, or phenyl groups.  
  10. A process according to claim 1, wherein said compound is represented by the formula R&#39;OOC-HN- NH-CH2-COOR&#34;,  
 wherein R and R&#34; are independently hydrogen, or monovalent aliphatic, cycloaliphatic, or aromatic residues.  
  11. A process according to claim 10, wherein said compound is represented by the formula