Antistatic compositions

Details Antistatic compositions Antistatic compositions

2001-11-05

2004-05-25

Jones, Deborah (Department: 1775)

Stock material or miscellaneous articles

Composite

Of fluorinated addition polymer from unsaturated monomers

C428S441000, C428S451000, C428S500000, C427S372200, C427S384000, C252S008610, C252S008910

Reexamination Certificate

active

06740413

ABSTRACT:

FIELD OF THE INVENTION
This invention relates to antistats or antistatic agents and compositions that exhibit antistatic characteristics. This invention further relates to fibers, films, fabrics, coatings, or molded or blown articles comprising the compositions. In other aspects, this invention relates to a topical treatment composition and to processes for imparting antistatic characteristics to insulating materials.
BACKGROUND OF THE INVENTION
Antistats or antistatic agents are used to dissipate electrostatic or static charge. Electrostatic charge buildup is responsible for a variety of problems in the processing and the use of many industrial products and materials. Electrostatic charging can cause materials to stick together or to repel one another. In addition, static charge buildup can cause objects to attract dirt and dust that can lead to fabrication or soiling problems and can impair product performance.
Sudden electrostatic discharges from insulating objects can also be a serious problem. With photographic film, these discharges can cause fogging and the appearance of artifacts. When flammable materials are present, a static electric discharge can serve as an ignition source, resulting in fires and/or explosions.
Electrostatic charge is a particular problem in the electronics industry, because modem electronic devices are extremely susceptible to permanent damage by electrostatic discharges. The buildup of electrostatic charge on insulating objects is especially common and problematic under conditions of low humidity and when liquids or solids move in contact with one another (tribocharging).
Static charge buildup can be controlled by increasing the electrical conductivity of a material. This can be accomplished by increasing ionic or electronic conductivity. The most common means of controlling static accumulation today is by increasing electrical conductivity through moisture adsorption. This is commonly achieved by adding moisture to the surrounding air (humidification) or by the use of hygroscopic antistatic agents, which are generally referred to as humectants because they rely on the adsorption of atmospheric moisture for their effectiveness. Most antistatic agents operate by dissipating static charge as it builds up; thus, static decay rate and surface conductivity are common measures of the effectiveness of antistatic agents.
Antistatic agents can be applied to the surface (external antistat) or be incorporated into the bulk (internal antistat) of the otherwise insulating material. Internal antistats are commonly employed in polymers such as plastics. Generally, internal antistats fall into one of the following classes: (1) ones that are mixed directly into a molten polymer during melt processing; (2) ones that are mixed into a polymer solution, coated, and dried, or (3) ones that dissolve into a monomer (with or without a solvent) that is subsequently polymerized.
Known antistatic agents cover a broad range of chemical classes, including organic amines and amides, esters of fatty acids, organic acids, polyoxyethylene derivatives, polyhydridic alcohols, metals, carbon black, semiconductors, and various organic and inorganic salts. Many are also surfactants and can be neutral or ionic in nature.
Many low molecular weight, neutral antistats have sufficiently high vapor pressures and thus are unsuitable for use at high temperatures (e.g., polymer melt processing) due to material losses that occur via evaporation. Many other neutral antistats have insufficient thermal stability to survive polymer melt processing or other high temperature processing conditions.
Most nonmetallic antistats are humectants that rely on the adsorption and conductivity of water for charge dissipation. Thus, their effectiveness is typically diminished at low atmospheric humidity. Because many of these antistatic agents are also water soluble, they are easily removed by exposure of the material to water (e.g., washing) and therefore are not very durable.
Metal salts of inorganic, organic, and fluoroorganic anions are also useful as antistatic agents in certain polymer compositions. Alkali metal salts are most commonly employed due to cost and toxicity considerations and to the high affinity of alkali metal cations, especially lithium, for water. But most metal salts are not compatible with polymers of moderate to low polarity, such as polypropylene, polyester, and polycarbonate. This incompatibility can result in inadequate antistat performance and/or an unacceptable reduction in physical properties or transparency in a finished polymeric article. Consequently, the use of metal salts as internal antistatic agents is generally limited to highly polar and/or hydrophilic polymer matrices.
Thus, there remains a need for antistatic agents to impart good antistatic characteristics to insulating materials in a cost effective manner and that, in particular, can be utilized as internal antistatic melt additives without suffering thermal decomposition, or causing processing problems or melt defects.
SUMMARY OF THE INVENTION
Advantageously, the present invention provides antistatic agents that exhibit good antistatic properties and that are melt processable. Briefly, in one aspect, the present invention provides antistatic agents comprising at least one polymeric salt. This salt consists of at least one cation having at least one polyoxyalkylene (POA) moiety bonded to a single ammonium center and a fluorinated anion. The cation(s) is represented by the following formula:
+
N[(R
1
)
4−y
][[POA]R
2
]
y
where POA is either a homopolymer or a copolymer that is random, blocked, or alternating, and POA comprises 2 to 50 units represented by the formula ((CH
2
)
m′
CH(R
3
)O) where each unit independently has m′, an integer from 1 to 4, and R
3
. R
3
is independently hydrogen or a lower alkyl group (i.e., containing 1 to 4 carbon atoms). R
1
is independently an alkyl, an alicyclic, an aryl, an alkalicyclic, an arylalicyclic, or an alicyclicaryl group that optionally contains one or more heteroatoms (e.g., sulfur, nitrogen, oxygen, chlorine, bromine, or fluorine). R
2
is independently hydrogen, an alkyl, an alicyclic, an aryl, an alkalicyclic, an arylalicyclic, or an alicyclicaryl group that optionally contains one or more heteroatoms (e.g., sulfur, nitrogen, oxygen, chlorine, bromine, or fluorine). And y is an integer from 1 to 4.
The fluorinated anion is represented by one of the following formulae:
R
f
SO
3
−
  (1)
−
O
3
SR
f2
SO
3
−
  (2)
where R
f
is independently a perfluoroalkyl, fluoroalkyl, or fluoroaryl group having from 1 to about 12 carbon atoms and R
f2
is independently a perfluoroalkylene, fluoroalkylene, or fluoroarylene group having from 1 to about 10 carbon atoms.
In another aspect, the present invention provides antistatic agents as polymer melt additives for thermoplastic polymers and as additives for thermoset polymers. The antistatic agents comprise at least one polymeric salt that consists of at least one cation having at least one polyoxyalkylene moiety bonded to a single ammonium center and a fluorinated anion.
The cation(s) is represented by the following formula:
+
N[(R
1
)
4−y
][[POA]R
2
]
y
where POA is either a homopolymer or a copolymer that is random, blocked, or alternating, and POA comprises 2 to 50 units represented by the formula ((CH
2
)
m′
CH(R
3
)O) where each unit independently has m′, an integer from 1 to 4, and R
3
. R
3
is independently hydrogen or a lower alkyl group (i.e., containing 1 to 4 carbon atoms). R
1
is independently an alkyl, an alicyclic, an aryl, an alkalicyclic, an arylalicyclic, and an alicyclicaryl group that optionally contains one or more heteroatoms (e.g., sulfur, nitrogen, oxygen, chlorine, bromine, or fluorine). R
2
is independently hydrogen, an alkyl, an alicyclic, an aryl, an alkalicyclic, an arylalicyclic, or an alicyclicaryl group that optionally contains one or more heteroatoms (e.g., sulf

Affiliated with

Also associated with

Rating

Antistatic compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Antistatic compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antistatic compositions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3229928