AKRON (July 18)—Myers Industries Inc. had net sales of $166.2 million for the second quarter ended June 30, up 13 percent from the $147.6 million reported in the like 1999 period. Net income fell 12 percent to $8 million from $9.2 million last year. For the six months ended June 30, sales jumped 19 percent to $327.8 million from $174.3 million in 1999´s first half. Net income fell 6 percent to $16.4 million from $17.3 million. The higher cost of plastics raw materials "is constraining earnings right now," according to Stephen E. Myers, president and CEO. Resin prices, he noted, have increased about 50 percent from the same period last year.