Unlock instant, AI-driven research and patent intelligence for your innovation.

Polymer materials with electrostatic dissipative properties

a technology of polymer materials and dissipative agents, applied in the direction of circuit electrostatic discharge protection, synthetic resin layered products, transportation and packaging, etc., can solve the problems of serious accidents, unsatisfactory static electrical charge, plastic materials have a tendency to accumulate static electrical charge, etc., and achieve the effect of propagating charg

Inactive Publication Date: 2006-06-08
NELSON GORDON L +1
View PDF13 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The invention is about polymers that have metallocene moieties added to them, which make them useful for controlling electrostatic discharge (ESD). These polymers can be used in applications where control of ESD is important. The metallocene moieties are added in a way that allows them to promote charge propagation. The percentage of metallocene in the polymer can be between 1% and 20%. The polymers can also be blended with other polymers or used as a coating on substrates to modify their ESD characteristics. The invention also includes new structures for electrostatic dissipative compositions.

Problems solved by technology

Plastic materials have a tendency to accumulate static electrical charges due to low electrical conductivity.
This static charge is undesirable for a variety of reasons, including dust attraction, interference with processing during fabrication of the final product, and spark generation from static buildup, which can produce serious accidents such as fire or explosion.
The increasing complexity and sensitivity of microelectronic devices make the control of static discharge of particular concern to the electronic industry, such as integrated circuit (IC) and semiconductor equipment manufacture.
Even a low voltage discharge can destroy or cause a latent defect in an electronic component.
These adverse effects are often seen when the electronic component is a solid state electronic device, such as a computer chip, which contains several semiconductive layers.
Thus, even relatively small electrostatic discharges of less than 500 V can burn through the semiconductor layer and induce latent defects in, or completely destroy the functionality of, the semiconductor layer.
The resistivity must not be so low as to allow the charge to move too quickly through material, thereby causing an arc or spark.
Dissipation of electric charge from polymer surfaces is often accomplished by the addition of various conductive chemicals, but these chemicals often have short life spans or toxic constituents.
However, these technologies have several manufacturing and performance limitations.
While blending conductive additives such as graphite and metals with a host polymer can increase conductivity and produce a dissipative solution, the finished product can suffer from a reduction in physical strength and inconsistent performance due to non-uniform distribution.
Another problem associated with conductive additives is migration.
At high temperatures (e.g., during processing or in field conditions), conductive additives tend to migrate to the surface of the polymer composition, which has a negative impact on both physical characteristics and ESD characteristics.
However, the ESD behavior of polymers containing a ferrocene moiety as a constituent of the polymer structure (as opposed to its use as an additive) has never been evaluated.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Polymer materials with electrostatic dissipative properties
  • Polymer materials with electrostatic dissipative properties
  • Polymer materials with electrostatic dissipative properties

Examples

Experimental program
Comparison scheme
Effect test

example 1

Ferrocene-Containing Hydroxyl Terminated (FCOH) Prepolymer Synthesis

[0061] A scheme for the synthesis of 1,1′-di(chlorocarbonyl) ferrocene is shown in FIG. 7. To the solution of 4.0 g (0.013 mole) 1,1′-di(chlorocarbonyl) ferrocene in dry benzene (95 ml), 1.82 g (0.0154 mole) 1,6-hexanediol and pyridine (1.1 ml) was added. The mixture was stirred at 70-75° C. under an inert atmosphere (N2 gas) for 4 hours. The pyridinium chloride salt, being insoluble in benzene was precipitated from the reaction phase. The mixture was filtered and the solvent was evaporated under reduced pressure. The residue was extracted with CH2Cl2 and washed with water. The organic layer was dried (Na2SO4) and evaporated to give 4.3 g (88%) of ferrocene containing hydroxyl terminated prepolymer, FcOH. 1H NMR of this compound showed an average molecular weight of −3600. 1H NMR δ: 4.83 (s, 4H), 4.40 (s, 4H), 4.24 (t, 4H), 3.68 (t, 0.43H), 1.78 (m, 4H), 1.52 (m, 4H). IR (cm−1, neat): 1722.9 (C═O), 2940.4 (CH aliph...

example 2

FCOH-Containing Block Copolyurethanes

[0062] Block copolymers were prepared by using the “prepolymer method.” The diisocyanate-terminated prepolymer (BAYTEC ME-080, Bayer Corporation, Pa.) was heated at 100-110° C. for about 30 minutes (diphenylmethane-4,4′-diisocyanate (MDI) / polytetramethylene ether glycol (PTMEG) based BAYTEC ME-080 prepolymers, with NCO content of 8.64%). To this, FcOH dissolved in tetrahydrofuran (THF) and several drops of T-12 catalyst solution (dibutyltin dilaurate) were added. The mixture was mechanically stirred under nitrogen for 20 minutes, and then HDO was added and stirred for one minute. The films were cast from THF, on TEFLON sheets, and were cured under vacuum at 80° C. for 6 hours.

example 3

Ferrocene-Containing Amine Terminated (FcNH2) Prepolymer Synthesis

[0063] To the solution of 7.0 g (0.023 mole) 1,1′-di(chlorocarbonyl) ferrocene in CH2Cl2 (70 ml), 3.1 g (0.027 mole) 1,6-hexanediamine and 1.8 g (0.045 mole) NaOH dissolved in H2O (30 ml) was added at one portion and stirred vigorously for 10 minutes. The precipitate was filtered and washed with CH2Cl2 to give 9.0 g (93%) of FcNH2. Molecular weight by end group analysis was 1381. IR (cm−1, KBr pellet): 1551 (amide II band), 1637.3 (amide I band), 2868.0 and 2940 (CH aliphatic), 3091.8 (CH olefin), 3309.0 (NH). A scheme for the synthesis of ferrocene-containing amine terminated (FcNH2) prepolymer is shown in FIG. 9.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
electrostatic dissipative characteristicsaaaaaaaaaa
molecular weightaaaaaaaaaa
charge dissipationaaaaaaaaaa
Login to View More

Abstract

A method for modifying the electrostatic discharge (ESD) characteristics of a polymeric material by integrating metallocene moieties as constituents of the polymer structure. In a preferred embodiment, the metallocene is part of the polymer backbone structure. In another preferred embodiment, the metallocene moieties are in sufficiently close proximity to one another such that electrostatic charge propagation is promoted. In another preferred embodiment, the metallocene is ferrocene. In another embodiment, an article is formulated from, or coated with, a polymeric composition containing metallocene as a polymer constituent. The subject invention includes novel polymeric compositions. Polymeric compositions of the subject invention, and articles made therefrom, exhibit electrostatic dissipative properties which are useful in preventing destructive electrostatic discharge.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application is a continuation of U.S. application Ser. No. 10 / 114,896, filed Apr. 1, 2002, which claims the benefit of provisional patent application Ser. No. 60 / 280,015, filed Mar. 30, 2001, each of which is hereby incorporated by reference herein in its entirety, including any figures, tables, nucleic acid sequences, amino acid sequences, and drawings.FIELD OF THE INVENTION [0002] The subject invention pertains to compositions useful as electrostatic dissipative agents and methods for making and using such compositions. BACKGROUND OF THE INVENTION [0003] Plastic materials have a tendency to accumulate static electrical charges due to low electrical conductivity. Friction between dissimilar electrical insulators can generate significant static charge in a short period of time (i.e., triboelectric charging). Floor surfaces, particularly in a manufacturing area, are subject to such charge generation by virtue of the movement ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): B32B27/40B32B27/34B32B27/36B32B27/32
CPCC08G18/10C08G18/38C08G2101/0008H05K1/0259H05K1/167H05K3/424H05K2201/0329C08G18/3823C08G2110/0008Y10T428/31504Y10T428/31551Y10T428/31725Y10T428/31786Y10T428/31938
Inventor NELSON, GORDON L.NAJAFI-MOHAJERI, NAHID
Owner NELSON GORDON L