The complaint
The case is Trade Associates, Inc. v. Powertec Industries Co., Ltd. and Southern Technologies LLC, No. 4:26-cv-11560 (N.D. Cal.), filed October 7, 2026, ECF No. 1, with a jury demand. Trade Associates says it is a Washington corporation based in Kent, Washington, that sells Dura-Block sanding blocks for automotive and marine refinishing. It alleges, on information and belief, that Powertec Industries Co., Ltd. is a Taiwan entity based in Taichung, and says Southern Technologies LLC is an Illinois limited liability company that has stated in filings in this court that its principal place of business is in Oakland, California. The docket shows the case assigned to Judge Araceli Martinez-Olguin.
The patents
The complaint asserts U.S. Patents 9,731,403 (issued August 15, 2017), 9,427,847 (August 30, 2016), 11,292,103 (April 5, 2022), and 9,975,220 (May 22, 2018), each titled Hand-Held Conformable Sanding Block. It says Trade Associates owns all four and marks its products with the patent numbers.
Claim 6 of the '403 patent, claim 1 of the '847 patent, claim 1 of the '103 patent, and claim 5 of the '220 patent each recite an elastomeric sanding block, conformable to curved or flat surfaces, with a Shore A hardness of about 30 to about 90, defined by the composition it is made from; claim 12 of the '403 patent and claim 6 of the '847 patent recite methods of making such a block. Claim 6 of the '403 patent recites a polymeric component consisting of ethylene-vinyl acetate copolymer at about 35 to about 70 percent of the composition by weight and a blowing agent at about 1.5 to about 4.5 percent; claim 12 recites making such a block by combining that copolymer with a blowing agent under heat, thermoforming the feedstock in a mold, and cutting the foamed sheet. Claim 1 of the '847 patent recites an admixture of about 70 to about 90 weight percent ethylene-vinyl acetate copolymer and about 10 to about 30 weight percent low-density polyethylene homopolymer, a blowing agent, and about 5 to about 18 weight percent pigment. Claim 1 of the '103 patent recites a similar admixture that adds a metallocene catalyzed ethylene-alpha-olefin copolymer, with a filler and a carbon pigment. Claim 5 of the '220 patent recites a composition free of ethylene-vinyl acetate copolymer, with low-density polyethylene homopolymer at about 35 to about 70 percent and a filler at about 25 to about 60 percent.
The Amazon takedowns and the alter ego allegations
The complaint alleges that Trade Associates filed two Amazon Patent Evaluation Express requests on or about June 23, 2026, against POWERTEC-branded sanding block listings, and that Amazon took the listings down shortly after. It alleges that a September 18, 2026 letter to Amazon from the defendants' counsel asserted that the blocks do not contain ethylene-vinyl acetate (EVA), while the defendants' own Amazon listings described the material as "EVA Foam," and it challenges the testing behind that letter. It also alleges that the individual who owns Southern Technologies, not either company, holds the POWERTEC trademark registrations, and that he and the two companies are alter egos of one another.
The counts and relief
Count I alleges, on information and belief, infringement of at least claims 6 and 12 of the '403 patent; Count II, claims 1 and 6 of the '847 patent; and Count III, claim 1 of the '103 patent. Count IV, pleaded in the alternative if some blocks do not contain EVA, alleges infringement of at least claim 5 of the '220 patent. Each count alleges willful infringement. The prayer asks for a judgment of infringement, damages of no less than a reasonable royalty with interest and costs, a finding of willfulness with trebled damages, an exceptional-case award of attorney fees, preliminary and permanent injunctions, and an order that the two defendants and the individual owner are jointly and severally liable.
What to watch next
The court's initial scheduling order sets a case management statement due December 31, 2026. Watch for service on the Taiwan defendant, the defendants' response, and any motion directed to the alter ego allegations. The case can end at any time, including by settlement or voluntary dismissal.