IMIDE-CONTAINING POLYSILOXANES AND A PROCESS FOR PREPARING THEM

Abstract: Disclosed are novel polysiloxanes containing imide terminal groups shown by formula (I) which can be prepared by the Michael addition reaction of a bismaleimide and a reactive polysiloxane. The polysiloxanes according to the present invention are useful as a modifying agent for synthetic resins. In said formula, R1 and R2, independent of each other, represent methyl, ethyl, propyl or phenyl; R3 represents an alkylene having carbon atoms of 1 to 8 or an alkyl substituted alkylene having carbon atoms of 1 to 8, whose terminals include secondary amine groups; n represents an integer of 30 to 400, which indicates the degree of polymerization of the polysiloxane; and A represents a divalent group having carbon atoms of at least 2, preferably 2 to 20.

Description: IHIDE-CONTAINING POLYSILOXANES AND A PROCESS FOR PREPARING THEM TECHNICAL FIELD The present invention relates to a novel polysiloxanes containing iiide terminal groups shown by the following forπula(I), and to a process for preparing them. Especially, the present invention relates to the polysiloxanes shown by the following formula( I ) which can be effectively used as the modifying agent in the field of synthetic resins. wherein Ri and R 2 , independent of each other, represent methyl, ethyl, propyl or phenyl; R 3 represents an alkylene having carbon atoms of 1 to 8 or an alkyl substituted alkylene having carbon atoms of 1 to 8, whose terminals include secondary amine groups; n represents an integer of 30 to 400, which indicates the degree of polymerization of the polysiloxane; and A represents a divalent group having carbon atoms of at least 2, preferably 2 to 20. Recently, there have been widely known various plastics which have been modified with siloxane compounds. For the purpose of modifying synthetic resins, polysiloxanes containing hydroxy terminal groups have been already used. In the GB patent So. 880,022, there is disclosed the method that a polyoxyalkylene is reacted with a polysiloxane containing two alkoxy groups at ends to give polyoxyalkylene-polysiloxanediol block copolymers. Also, a process for preparing new polysiloxanes containing hj'droxy terminal groups is proposed in the US patent No. 3,981,898, in which polysiloxanes containing hydroxy terminal groups are prepared by reacting polysiloxanes with polyols and diols. But, when said polysiloxanes were used as the modifying agents of the thermosetting resins such as unsaturated polyester, epoxy resins and the like, there was disadvantage in that an excess of flash was occurred during the molding process. On the other hand, in the DE patent No. 1,618,836, there are used trisiloxanols, having hydroxy groups directly bonded to Si atoms, as the plastic modifier. However, such siloxanol compounds have a disadvantage that it is difficult to process them with organic resins and hence they cannot be suitably used as modifying agents for synthetic resins. Therefore, the present inventors have eagerly studied to overcome the prior disadvantages as described above, and consequently we have developed novel polysiloxanes containing imide terminal groups which are effectively used as a modifying agent for especially thermosetting resins such as unsaturated polyester, epoxy resin, polyamide and so on. SUMMARY OF THE INVENTION An object of the present invention is to provide new polysiloxanes whose both terminals are substituted by imide groups, which are shown by the formula( I ). Another object of the present invention is to provide a process for preparing the polysiloxanes containing imide terminal groups which are shown by the formula( I ). DISCLOSURE OF THE INVENTION The present invention relates to the polysiloxanes containing terminal groups shown by the following formula(I), which may be prepared by the Michael addition reaction of a bismaleimide shown by the following fonula(II) and a polysiloxane shown by the following formula(E) at a temperature of 110 to 150 °C R 3 '— - Si -O-fcHfe * (ffl) wherein Ri and R 2 , independent of each other, represent methyl, ethyl, prop5 r l or p enyl; R 3 represents an alkylene having carbon atoms of 1 to 8 or an alkyl substituted alkylene having carbon atoms of 1 to 8, whose terminals include secondary amine groups; R a ' represents a primary amine corresponding to R 3 ; n represents an integer of 30 to 400, which indicates the degree of polymerization of the polysiloxane; A represents a divalent group having carbon atoms of at least 2, preferably 2 to 20; and B represents a divalent group having carbon atoms of at least 2, preferably 2 to 6, which contains a carbon-carbon double bond. In the present invention, the bismaleimides of the formula(II) include, for example, N,N ' -1 ,3-pheiιylene bismaleimide, N,N'-4,4'- -diphenylmethane bismaleimide, N'.K'-4,4 ' -diphenylether bismaleimide, N',N'-4,4'-diphen>lsulfone bismaleimide, N,N'-3,4'-diphenylsulfone bismaleimide, ,K'-4,4'-dimethylcyclohexane bismaleimide, N,N'-4, 4'-diphenylcyclohexane bismaleimide, N,N'-l,3-xylilene bismaleimide, 2,4-bismaleimide toluene, 2,6-bismaleimide toluene, and so on. And, the polysiloxanes of the formula(Iϋ) include, for example, poly(dimethyl siloxane), poly(methylphenyl siloxane), poly(epoxy- modified siloxane), poly(dimethyl siloxane)-co-poly(diphenyl siloxane), fatty acid-modified polysiloxane, polysiloxane-polyether copolymer, and so on. According to the present invention, the bismaleimide of the formula(II) is preferably used in an amount of 3 to 10 parts by weight, more preferably 4 to 7 parts by weight, to the polysiloxane of the formula(HI) of 30 to 100 parts by weight, more preferably 40 to 60 parts by weight. The polysiloxanes containing imide terminal groups of the formula(I) which are prepared in accordance with the present invention have some advantages, for example, they have good compatibility with organic resins, and then they can be preferably used as the modifying agents thermosetting resins such as unsaturated polyester, epoxy resins, polyamide, etc. and also thus modified resins show markedly shortened flash lengths when molded. This invention will be further described in detail with the following examples. It should be noted that the present invention is no limited to these examples. And, the material properties of the resin compositions which have been prepared by Examples and Comparative examples were evaluated by the method as follows: Flexural Strength ; ASTM D-790 Flexural Modulus ; ASTM D-790 Preparation 1 50g of reactive poly(dimethyl siloxane were put in a lOOmfi three- neck flask equipped with a stirrer and a thermometer, and preheated to 130 'C. After δg of N,N'-4, '-diphenylmethane bismaleimide were added therein, the mixture was reacted for 10 minutes at 130 °C with stirring. When the reaction mixture turns into a highly viscous phase, and it was cooled down to room temperature to give the objective polysiloxane. Elementary Analysis S ; 1.8%, C ; 33.2%, H; 8.28% IR (cm -1 ) -NH £ ; v = 3,600 (disappeared in the reaction product) -NH ; v - 3,750 -C-N ; v = 1,350 Preparation 2 50g of reactive poly(methylphenyl siloxane) and 6.5g of N,N'- diphenylether bismaleimide were put in a lOOmfl three-neck flask equipped with a stirrer and a thermometer. The reaction mixture was heated for 10 minutes at 140 °C with stirring. At the completion of the reaction, the highly viscous reaction mixture was cooled down to room temperature to give the objective polysilioxane. Elementary Analysis 5 ; 2.1%, C ; 32.5%, H; 7.4% IR (cm "1 ) -NH Z ; v = 3,610(disappeared in the reaction product) -NH ; v = 3,730 -C-S ; v = 1,320 NMR(ppm) -N-H ; δ = 0.6 Example 1 5g of the polysiloxane obtained by Preparation 1 and 95g of cresol novolak epoxy resin having epoxide equivalent weight of 213 were put in a 300m)2 three-neck flask equipped with a stirrer and a theruometer and intensely stirred for about an hour at 150~160 C C to obtain a resin mixture. The obtained mixture was designated as Mixture A. After cooling down the mixture to room temperature, novolak resin having hydroxy equivalent weight of 306, as curing agent, l.lg of triphenyl phosphine as curing accelerator, 3g of calcium stearate as releasing agent, and 337g of silica powder. The obtained composition was melt-mixed using a mixer such as an extruder, a kneader and rolls. After suddenly cooling down the composition in the stage B to room temperature and finely pulverizing it, the pulverized composition was put in an aluminum mold preheated to 175 °C, and cured for 3 minutes. At this moment, the aluminum molds which had gaps of 0.005, 0.01 and 0.02 inch, were used for measuring the length of flash produced during molding process. Then, the cured composition was used for measuring the material properties, and the results were shown in Table 1. Example 2 5g of the polysiloxane obtained by Preparation 2 and 95g of the resin composition prepared by Example 1 were put in a 300m£ three- neck flask equipped with a stirrer and a thermometer, and intensely stirred for about an hour at 150'-'160°C. Thus obtained mixture was designated as Mixture B. After cooling down the mixture to room temperature, 80g of this mixture were mixed in a mechanical mixer with the same additives as the foregoing Example 1. Hereinafter the procedure was the same as in Example 1, and then the results were shown in Table 1. Comparative example 1 5g of the poly(dimethyl siloxane) used in Preparation 1 and 95g of the epoxy resin used in Example 1 were put in a 300mfi three-neck flask equipped with a stirrer and a thermometer, and intensely stirred for about an hour at 150^'160 o C. The obtained mixture was designated as Mixture C. After cooling down the mixture to room temperature, 80g of this mixture were mixed in a mechanical mixer with the same additives as used in Example 1. Hereinafter the procedure was the same as in Example 1, and the results were shown in Table 1. Comparative example 2 5g of the pol (methylphenyl siloxane) used in Preparation 2 and 95g of the epoxy resin used in the Example 1 were put in a 300m_Q three-neck flask equipped with a stirrer and a thermometer, and intensely stirred for about an hour at 150^160°C. The obtained mixture was designated as Mixture D. After cooling down the mixture to room temperature, 80g of this mixture were mixed in a mechanical mixer with the same additives as used in Example 1. Hereinafter the procedure was the same as in Example 1, and the results were shown in Table 1. Tab l e <Note> * : When the mold having a gap of 0.005 inch was used. ** : When the mold having a gap of 0.01 inch was used. *** : When the mold having a gap of 0.02 inch was used. As shown in Table 1. the resin compositions, which comprise the polysiloxanes containing imide terminal groups according to the present invention, have considerably short flash lengths, improved flexural strength, and then excellent, processability. In conclusion, the present invention provides novel polysiloxanes containing imide terminal groups which are shown by the formula ( I ) and which can be effectively used as a modifying agent for synthetic resins.

Claims: Claims : 1. Polysiloxanes containing imide terminal groups which are shown by the formula( I ) wherein Ri and RE, independent of each other, represent methyl, ethyl, propyl or phenyl; R 3 represents an alkylene having carbon atoms of 1 to 8 or an alkyl substituted alkylene having carbon atoms of 1 to 8, whose terminals include secondary amine groups; n represents an integer of 30 to 400, which indicates the degree of polymerization of the polysiloxane; and A represents a divalent group having carbon atoms of at least 2, preferably 2 to 20. 2. A process for preparing the polysiloxanes containing imide groups shown by the formula( I ), which is characterized by comprising the Michael addition reaction of a bismaleimide shown by the formula (II) and a polysiloxane shown by the formula(ID) at a temperature of 110 to 150 β C. wherein Ri and R 2 , independent of each other, represent methyl, ethyl, propyl or phenyl; R 3 represents an alkylene having carbon atoms of 1 to 8 or an alkyl substituted alkylene having carbon atoms of 1 to 8, whose terminals include secondary amine groups; R 3 ' represents a primary amine corresponding to R 3 ; • n represents an integer of 30 to 400, which indicates the degree of polymerization of the polysiloxane; A represents a divalent group having carbon atoms of at least 2, preferably 2 to 20; and B represents a divalent group having carbon atoms of at least 2, preferably 2 to 6, which contains a carbon-carbon double bond. 3. The process according to Claim 2, in which the bismaleimide shown by the formula(II) is selected from the group consisting of N,N'-1,3- phenylene bismaleimide, N,N'-4,4'-diphenylmethane bismaleimide, N,N'- 4,4'-diphenylether bismaleimide, N,N'-4,4'-diphenylsulfone bismaleimide, N,N l -3, '-diphenylsulfone bismaleimide, , '-4,4'-dicyclohexylmethane bismaleimide, N,N'-4,4'-dimethylcyclohexane bismaleimide, N, '-4,4'- diphenyleyelohexane bismaleimide, N, '-l,3-xylilene bismaleimide, 2,4- bismaleimide toluene, and 2,6-bismaleimide toluene. - 17 - 4. The process according to Claim 2, in which the polysiloxane shown by the formula(III) is selected from the group consisting of poly(dimethyl siloxane), poly(methylphenyl siloxane), poly(epoxy-modified siloxane), poly(dimethyl siloxane)-co-poly(diphenyl siloxane), fatty acid-modified polysiloxane,and polysiloxane-polyether copolymer.

Inventors: KIM MYUNG JOONG, PARK JUNG OK, SONG JU OK, KIM, MYUNG, JOONG, PARK, JUNG, OK, SONG, JU, OK
Applicants: LUCKY LTD, LUCKY, LTD.
Application year: 1989
Main classification: C08G77
IPC codes: C08G77, C08L101