Crude MDI의 정제 및 Monomeric MDI의 안정화에 관한 연구

정종원; 김영철; 박남국

Journal of the Korean Industrial and Engineering Chemistry, Vol.7, No.3, 588-596, June, 1996

Export Citation

Crude MDI의 정제 및 Monomeric MDI의 안정화에 관한 연구

A Study on the Stabilization of Monomeric MDI and Purification of Crude MDI

정종원, 김영철, 박남국

초록

Crude MDI를 정제하여 고순도의 Monomeric MDI와 반응성이 양호한 Polymeric MDI를 얻기 위해 1차 및 2차 증류의 최적조건을 검토하였으며, Monomeric MDI의 변색 및 중합방지를 위하여 첨가제 사용 실험을 하였다. 또한 Polymeric MDI는 표준 Polyol system으로 우레탄 반응을 유도하여 반응성을 조사하였다. 1차 증류에서 증류분이 약 32wt%일 때 4,4'-MDI의 함량이 98wt% 이상으로 유지되었으며, 2차 증류에서는 2,4'-MDI의 혼입을 최소화하기 위해 초류분을 약 20wt% 분리하고 잔류분으로 약 9wt%를 남겼다. 환류비를 2이상으로 유지했을 때 최종 증류분인 Monomeric MDI의 응고점은 38.4℃ 이상으로 나타났다. Monomeric MDI는 매우 불안정하여 착색이 용이하고 자체 중합체를 형성한다. 따라서 이를 방지하기 위해 페놀계 1차 산화방지제 및 인계 2차 산화방지제, UV 흡수제, Hindered amine계 광안정제를 조합하여 사용하고, 중합방지제로는 Benzoyl chloride를 사용한 결과 45일 경과 후에도 색은 APHA 20이하이고, Dimer 생성율은 0.36wt% 이하로 유지되었다.

The optimum conditions of the 1st and 2nd distillation had been investigated to obtaine a high quality monomeric MDI and fire reactive polymeric MDI by purification of crude MDI. Effect of additives on the monomeric MDI's color change, dimerization and the reactivity of polymeric MDI with standard polyol system has been tested. When the monomeric MDI yield is approximately 32%, 4,4'-MDI content is above 98% in the monomeric MDI at the 1st distillation. When the separation ratio of initial portion and residue percentage, reflux ratio are set at respectively, approximately 20wt%, 9wt%, above 2 in order to minimize the content of 2,4'-MDI in monomeric MDI, the freezing point of final distilled monomeric MDI is above 38.4 ℃. Since the monomeric MDI is inherently unstable in the room condition, monomeric MDI easily changes it's color and conducts self-polymerization reaction. To increase the stability of monomeric MDI, the composition of antioxidant, which is composed of phenolic 1st antioxidant, phosphorus 2nd antioxidant, UV absorbent and Hindered amine light stabilizer are used, and benzoyl chloride as antipolymerization agent test are that APHA color is less than 20, dimer content is remained less than 0.36 wt% after 45 days storage of monomeric MDI.

[References]

Oertel G, "Polyurethane Handbook," Macmillan Publishing Co., New York (1985)
Twitchett HJ, Chem. Soc. Rev., 3, 209 (1974)
Kan PT, MDI Chem., Aug., 34 (1980)
Raiford LC, Freyermuth HB, J. Org. Chem., 28, 2069 (1963)
Campbell TW, Smeltz KC, J. Org. Chem., 28, 2069 (1963)
Dyer E, Read RE, J. Org. Chem., 26, 4677 (1961)
Neumann W, Fischer P, Angew. Chem.-Int. Edit., 74, 801 (1962)
Khorana HG, Chem. Rev., 53, 145 (1953)
Fondots DC, J. Cell. Plast., 11, 250 (1975)
Neet TE, Degisi SL, J. Cell. Plast., 11, 174 (1973)
Critchifield PE, Koleske JV, "Advance in Urethane Science & Technology," Hanser Publisher, New York, Vol. 2 (1971)
Hamann H, Tschemko G, Plast. Kautsch, 26, 619 (1979)
Kanner B, Prokai B, Eschbach CS, Murphy GI, J. Cell. Plast., 15, 315 (1979)
Dubjaga IG, Titarowa G, Tarakanow OG, Hamann H, Tschemko G, Plast. Kautsch., 26, 616 (1979)
Rosemund WR, Sandner MR, J. Cell. Plast., 13, 182 (1977)
Lovely EW, Hargis JD, Plast. Eng., Nov., 32 (1979)
Calvert PD, Tyan TG, Polymer, 19, 611 (1978)

[Referenced By]

[1] Oertel G, "Polyurethane Handbook," Macmillan Publishing Co., New York (1985)

[2] Twitchett HJ, Chem. Soc. Rev., 3, 209 (1974)

[3] Kan PT, MDI Chem., Aug., 34 (1980)

[4] Raiford LC, Freyermuth HB, J. Org. Chem., 28, 2069 (1963)

[5] Campbell TW, Smeltz KC, J. Org. Chem., 28, 2069 (1963)

[6] Dyer E, Read RE, J. Org. Chem., 26, 4677 (1961)

[7] Neumann W, Fischer P, Angew. Chem.-Int. Edit., 74, 801 (1962)

[8] Khorana HG, Chem. Rev., 53, 145 (1953)

[9] Fondots DC, J. Cell. Plast., 11, 250 (1975)

[10] Neet TE, Degisi SL, J. Cell. Plast., 11, 174 (1973)

[11] Critchifield PE, Koleske JV, "Advance in Urethane Science & Technology," Hanser Publisher, New York, Vol. 2 (1971)

[12] Hamann H, Tschemko G, Plast. Kautsch, 26, 619 (1979)

[13] Kanner B, Prokai B, Eschbach CS, Murphy GI, J. Cell. Plast., 15, 315 (1979)

[14] Dubjaga IG, Titarowa G, Tarakanow OG, Hamann H, Tschemko G, Plast. Kautsch., 26, 616 (1979)

[15] Rosemund WR, Sandner MR, J. Cell. Plast., 13, 182 (1977)

[16] Lovely EW, Hargis JD, Plast. Eng., Nov., 32 (1979)

[17] Calvert PD, Tyan TG, Polymer, 19, 611 (1978)