Crystallization-free glass frit compositions and frits made therefrom for microreactor devices

Abstract

The invention is directed to a glass composition that can be used to make glass frits suitable for use in the manufacturing of microreactors. The glass compositions, after final sintering to produce a finished microreactor, have a surface crystalline layer of 30 μm or less, or are completely amorphous throughout. Generally, the borosilicate glasses of the invention have a composition of B 2 O 3 =12-22 mol %; SiO 2 =68-80 mol % and additional components selected from the group consisting of either (a) Al 2 O 3 =3-8 mol % and Li 2 O=1-8 mol %, or (b) K 2 O=0-2 mol % and Na 2 O=0-2 mol %, except that both K 2 O and Na 2 O cannot both equal zero at the same time. One borosilicate glass has a composition, in mole percent (mol %) of B 2 O 3 =18-22 mol %, SiO 2 =75-80 mol %, K 2 O=0-2 mol %, and Na 2 O=0-2 mol %, except that both K 2 O and Na 2 O cannot both equal zero at the same time.

1 . A borosilicate glass composition suitable for manufacturing microreactor glass frits, said borosilicate glass comprising a base glass composition in mole percent (mol %) of: 
 B 2 O 3 =12-22 mol %    SiO 2 =68-80 mol %, and    additional components selected from the group consisting of:    either: 
 (a) Al 2 O 3 =3-8 mol % and Li 2 O=1-8 mol %  
   or 
 (b) K 2 O=0-2 mol % and Na 2 O=0-2 mol %, except that both K 2 O and Na 2 O cannot both equal zero at the same time;  
   wherein when said glass composition is the base glass composition and (a), said composition can optionally further comprise one or more substances selected from the group consisting of calcium oxide in an amount of 1.0 - 1.4 mol %, zirconium oxide in an amount of 0.5±0.1 mol %, fluorine (F) in an amount less than 1.5 mol %, and sodium oxide (Na 2 O) in an amount less than 3 mol %; and    wherein after sintering a glass frit having said composition has a surface crystalline layer of 30 μm or less, or is amorphous throughout.    
   
   
       2 . The glass according to  claim 1 , wherein said glass comprises: 
 SiO 2 =72.6±2 mol %,    B 2 O 3 =13.4±2 mol %,    Al 2 O 3 =6.5±1 mol %,    Li 2 O=6.9±1 mol %, and    ZrO 2 =0.5±0.25 mol %; and    wherein after sintering said glass frit is amorphous throughout.    
   
   
       3 . The glass according to  claim 1 , wherein said glass comprises: 
 SiO 2 =70.2±2 mol %,    B 2 O 3 =20.4±2 mol %,    Al 2 O 3 =3.4±1 mol %,    Li 2 O=1.4±0.8 mol %,    Na 2 O=2.3±0.5 mol %,    CaO=1.1±0.5 mol % and    F=1.1±0.5 mol %; and    wherein after sintering said glass frit is amorphous throughout.    
   
   
       4 . The glass according to  claim 1 , wherein said glass comprises: 
 SiO 2 =78.1±2 mol %,    B 2 O 3 =20.4±2 mol %, and    K 2 O=1.6±0.8 mol %; and    wherein after sintering said glass frit have a surface crystalline layer of 10 μm or less.    
   
   
       5 . A glass according to  claim 1 , wherein said glass comprises: 
 SiO 2 =78.0±0.5 mol %,    B 2 O 3 =20.4±0.5 mol %,    K 2 O=0-1.2±0.2 mol %, and    Na 2 O=0.4-1.2±0.2 mol %.    
   
   
       6 . A glass composition according to  claim 5 , wherein said glass comprises: 
 SiO 2 =78.0±0.5 mol %,    B 2 O 3 =20.4±0.5 mol %,    K 2 O=0.4±0.2 mol %, and    Na 2 O=1.2±0.2 mol %.    
   
   
       7 . A glass composition according to  claim 5 , wherein said glass comprises: 
 SiO 2 =78.0±0.5 mol %,    B 2 O 3 =20.4±0.5 mol %, and    K 2 O=0 mol %, and    Na 2 O=1.0±0.2 mol %.    
   
   
       8 . The glass according to  claim 1 , wherein said glass has a softening point of 825° C. or less.  
   
   
       9 . The glass according to  claim 1 , wherein said glass has a softening point of 800° C. or less.  
   
   
       10 . The glass according to  claim 1 , wherein said glass has a softening point of 780° C. or less.  
   
   
       11 . The glass according to  claim 5 , wherein said glass has a softening point of 800° C. or less.  
   
   
       12 . The glass according to  claim 1 , wherein said glass has a CTE in the range of 25-40×10 −7 /° C.  
   
   
       13 . The glass according to  claim 5 , wherein said glass has a CTE in the range of 25-35×10 −7 /° C.  
   
   
       14 . The glass according to any one of claims  1 , wherein in a sintered glass frit the mismatch value of said frit with a substrate is less than −20 ppm.  
   
   
       15 . A borosilicate glass frit having a composition in mole percent (mol %) of B 2 O 3 =18-22 mol %, SiO 2 =75-80 mol %, K 2 O=0-2 mol %, and Na 2 O=0-2 mol %, except that both K 2 O and Na 2 O cannot both equal zero at the same time.  
   
   
       16 . The borosilicate glass frit according to  claim 15 , wherein said glass frit has a softening point less than 800° C.  
   
   
       17 . The borosilicate glass frit according to  claim 15 , wherein said glass frit has a CTE in the range of 25-35×10 −7 /° C.  
   
   
       18 . The borosilicate glass frit according to  claim 15 , wherein after sintering said sintered glass frit has a crystallization layer of 10 μm or less.  
   
   
       19 . The borosilicate glass frit according to  claim 15 , wherein said glass frit comprises SiO 2 =78.0±0.5 mol %, B 2 O 3 =20.4±0.5 mol %, K 2 O=0-1.2±0.2 mol %, and Na 2 O=0.4-1.2±0.2 mol %.  
   
   
       20 . The borosilicate glass frit according to  claim 15 , wherein said glass frit further comprises a filler selected from the group consisting of: 
 (a) β-eucryptite, a lithia-alumino-silicate composition with an intrinsic CTE of −10×10 −7 /° C;    (b) Stuffed β-quartz, a lithia-alumino-silicate composition with Zn and/or Mg partially replacing some of the Li and that has an intrinsic CTE=0×10 −7 /° C.; and    (c) β-spodumene, a lithia-alumino-silicate composition with Zn and/or Mg partially replacing some of the Li and that has an intrinsic CTE=+10×10 −7 /° C.    
   
   
       21 . The glass according to any one of claims  15 , wherein in a sintered glass frit the mismatch value of said frit with a substrate is less than −20 ppm.