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New Polyvinyl Acetal Resin for conductive paste New Developed plasticizer

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New Polyvinyl Acetal Resin for conductive paste New Developed plasticizer Powered By Docstoc
					New Developed Materials for Advanced Electro-Ceramics

1.Background
  MLCC development trends are moving towards thinner green sheet. Accordingly, Customers
  are demanding binder resins which improve green sheet strength, lamination properties, etc.
2.New Polyvinyl Acetal Resin for conductive paste
 Development Progress
 Sekisui Chemical’s ongoing R&D program has developed a new polyvinyl acetal resin for use
 as
 a temporary binder for screen printing pastes. SEKISUI’s New Resin exhibits excellent
 screen-printing characteristics and offers advantages over traditional alternatives.
 Properties
 Properties of New Resin, General PVB and Ethyl cellulose STD-100 are compared below:
       TableⅠ Properties
       Properties
                                    New Resin       General PVB      Ethyl cellulose

       Screen-printing                  ○                  ×              ◎
       Adhesion                         ◎                  ◎              ×
       Thermal decomposition            ○                  ○              △
       Dispersion of powders            ◎                  ◎              ○
       Flexibility                      ○                  ○              △
       Quality stability                ◎                  ◎              ×
       Delivery stability               ◎                  ◎              △

 Screen Printing Characteristics
 SEKISUI New Resin exhibits excellent screen printing characteristics, giving crisp, clean
 lines, without defects or stringing. Three types of binders were compared (SEKISUI
 New Resin, general PVB and ethyl cellulose).
 Scanning Electron Microscope photographs of screen printed
 pastes are shown below.
 Paste composition
 Metal : Ni (average of particle size : 0.4 µm)
 Ceramics : BaTiO3 (average of particle size : 0.1 µm)
 Solvent : α-terpineol
 Dispersing agent* : Lauric acid diethanol amide (obtained from Kao corporation)
 Binder : [1] SEKISUI New Resin : good screen-printing characterisitics
         [2] General PVB : poor screen-printing characterisitics
         [3] Ethyl cellulose (commonly used binder for screen-printing )
             New Resin                       General PVB               Ethyl cellulose




                OK                       Defects Present                     OK
Adhesion between Conductive Layer and Green Sheet
Adhesion was evaluated by measuring adhesion strength after heat pressing. Test conditions
and results are shown below:
Conductive Layer : same as for screen printing tests above
Green Sheet :       BaTiO3, ethanol/toluene, PVB

                                                                             FigureⅠ Adhesion srength
   conductive layer
                                             green sheet




                                                                              Tensile strength(gf/cm2)
                                                                                                         50
                                                                                                         40
                                                                                                         30                                    New Resin
                                                                                                         20                                    STD-100
                                        Heater
                                                                                                         10
                                                                                                          0
                                                                                                              40     60        80      100    120   140
           Press and Release                                                                                                 temperature(℃)



         SEKISUI New Resin is superior to STD-100 for adhesion strength.



Thermo Gravimetric Properties
Thermal decomposition characterisitics were determined by residual carbon measurement after
fired firing at 450℃ in air. (FigureⅡ)


          FigureⅡ TG-curve

                            100        100

                                                                                                                     New Resin
                             10
                                                                                                                     STD-100
            residual(wt%)




                              1

                                               0.2        0.22                                                            0.18
                             0.1
                                               0.06
                                                          0.02                                                            0.02
                            0.01
                                   0                 50            100                                        150           200
                                                                 time(min)


       The Residue for SEKISUI New Resin is lower than for Ethyl-cellulose.




                                                                                                                    SEKISUI CHEMICAL CO., LTD.
3. New plasticizer 「G-260」 for Green Sheet
  Scope
  To develop suitable plasticizers for Polyvinyl Butyral(PVB) Resins in ceramic binder applications.

  Characteristics (See TableⅠ)
    a) Excellent plasticizing characteristics for PVB Resins
    b) low volatilisity ( → easy handling )
    c) low environmental impact ( G-260 is non-phthalic acid derivative )
     TableⅠ Comparison with other plasticizers
                                                                              General plasticizer
                                                                                                                          G-260
     properties                                                           DOP       DBP           DOA
     Plasticizing Characteristics                                          ○           ○                ◎                  ◎
     Low-volatilisity                                                      ○           ×                △                  ○
     Includes Phthalic Acid derivatives?                                  yes(×)     yes(×)           no(○)               no(○)
     ※DOP(Dioctyl Phthalate), DBP(Dibutyl Phthalate), DOA(Dioctyl Adipate)

  Flow Temperature Comparison With Other Plasticizers
                                                                                                      Pressure
     Method :
     Test material is made by dissolving specified                                                    100kg/cm2
     amounts of PVB resin (SEKISUI's BM-S)
     and plasticizer in a solvent of
     Ethanol/Toluene at 50wt%/50wt%. The film                                                   Heating up
     (thickness approx. 60 microns) is cast on                                                  6℃/min.
     PET film and dried at the specified                                           sample
     temperature. Using this film sample,  the
     Flow-Temperature (Tf) is measured using
     the SHIMADZU Flow Tester.
                                                                                            Φ1mm×10mm
                                                                                                 -3
                        Tf (Flow Temperature) = Temperature at Flow Speed 1×10                         ml/sec

     FigureⅠ Flow Temperature of BM-S/Plasticizer=100/30

                                100                                                                   Drying Conditions
                                                                                                        BM-SZ only
      Flow Rate  ×10  (cm /s)
      3




                                                                                                        DOP(60℃×20min.)
      -4




                                                                                                        DOA(60℃×20min.)
                                 10
                                                                                                        DBP(60℃×20min.)

                                                                                                        G-260(60℃×20min.)

                                  1
                                      60   70   80   90   100 110 120 130 140 150 160 170 180
                                                              Temp. (℃)
TableⅡ Flow Temperature of BM-S/Plasticizer=100/30
        BM-S      BM-S/DOP      BM-S/DBP      BM-S/DOA                                              BM-S/G-260
         only        100/30       100/30         100/30                                               100/30
 Tf     149℃          95℃          91℃            86℃                                                  88℃
※Drying Condition : 60℃×20min.

                                       Low Tf → Softer PVB            → Higher Plasticizing Ability


FigureⅡ Volatility Comparison for Tf (Drying condition changed)
                                                                                              Drying Conditions
                            100
  Flow Rate  ×10  (cm /s)




                                                                                                BM-SZ only
 3




                                                                                                DOP(140℃×20min.)
 -4




                             10                                                                 DOA(140℃×20min.)

                                                                                                DBP(140℃×20min.)

                                                                                                G-260(140℃×20min.)
                              1
                                  60   70   80     90   100 110 120 130 140 150 160 170 180
                                                            Temp. (℃)


TableⅢ Volatility Comparison for Tf
        BM-S        BM-S/DOP     BM-S/DBP                                            BM-S/DOA       BM-S/G-260
         only        100/30        100/30                                             100/30          100/30
 Tf’    149℃          102℃          149℃                                               110℃           100℃
※Drying Condition : 140℃×20min.

Tf (Flow Temperature) increases when the PVB/Plasticizer film is dried at 140℃ for
20 minutes. This is caused by plasticizer volatilization. Plasticizer DBP in particular,
may volatilize completely. In contrast, plasticizer G260 shows very low volatility.


Result :
G-260 shows :                                    • Excellent Plasticizing Characteristics For PVB Resins
                                                 • Low-Volatility



Conclusion
SEKISUI Addresses Customer Demands With The Development Of
Advanced New Materials For Advanced Electro-Ceramics.


                                                                                    SEKISUI CHEMICAL CO., LTD.

				
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