Patricia Dishon entered the job market as a working mother at a Baltimore box factory in the 1960s, when her take-home pay was $98 a week. But the cost of day care for her four children would have been $112 a week, so she was forced to recruit family, friends and neighbors to help look after her children.

Twenty years later, one of Dishon's daughters has a 3-year-old child of her own -- and confronts the same problem. "She earns minimum wage. She can't afford a baby-sitter, and a day care center would take more than three-quarters of her salary," Dishon said.

"Not much has changed . . . . You can't afford to quit your job to stay home with the kids. These same problems are still facing women today," said Dishon, 44, who now works at Bethlehem Steel in Baltimore and belongs to the United Steelworkers of America.

Dishon was among the speakers yesterday who urged a national conference of the Coalition of Labor Union Women to prod labor unions to make employer-assisted day care a top priority at the bargaining table and to seek action in Congress to make child care a national priority.

The lack of affordable day care keeps many women from working, causes increased absenteeism from jobs and higher turnover, reduces productivity and heightens family stress, according to participants at the gathering of 125 union officials at the Washington Hilton.

"Show me a working mother and I'll show you a woman filled with guilt," Joyce D. Miller, coalition president, told the group, which heard women workers such as Dishon describing problems of day care and various forms of sex discrimination on the job.

Miller, one of only two women on the AFL-CIO's 35-member governing executive council, said she is "sick and tired of hearing the Moral Majority" and other groups attribute the decline of families to mothers working outside the home. Growing numbers of families depend on a second income or on the income of single mothers, she said, but the government has been slow to acknowledge the need for improved child care.

"The Reagan administration is not profamily. In fact this administration has done more than any other to destroy the American family . . . by slashing funds for day care . . . dismantling affirmative action, cutting funds for education" and reducing Medicare, Medicaid and other domestic programs, Miller said.

About 2,000 companies offer some form of child care assistance, according to a recent survey by The Conference Board, a corporate research group. Of those, about 120 firms and 400 hospitals offer on-site or nearby child care, about 500 supply financial assistance and the remainder offer child care referral and other services.

Most companies, especially in urban areas, argue that rents are too high to provide their employes with a nearby day care site, said Toby McIntosh, who negotiated for the Newspaper Guild in an unsuccessful effort to get on-site child care at the Bureau of National Affairs, a Washington publishing firm.

But the BNA did agree to allow employes to use personal sick leave to care for children and to help set up a Washington area child care referral service, he said.

Arnold Mayer, legislative director of the 1 million-member United Food and Commercial Workers union, said the deficit-cutting mood of Congress makes federal day care support highly unlikely in the near future. He said right-wing opponents have previously argued that children will be "sovietized or collectivized" if the federal government gets involved in such facilities.

But he said supporters have begun overcoming such opposition and could succeed in winning expanded tax incentives or other federal support for day care in coming years.

David Sweeney, a Teamsters union legislative specialist, said that local school boards are more receptive than federal officials to day care demands, and he urged unions to try to organize local lobbying efforts for preschool and after-school programs to aid working families. "Day care," Sweeney said, "is absolutely essential at your bargaining tables . . . and in your communities."