Java GridBagLayout column size

With this code I can easily add some components to the layout. But now, as you can see from the image, I want the JTextField to go beyond its own half … how can I do?

private JPanel createButtonPanel() {
    JPanel pane = new JPanel(new GridBagLayout());

    JButton button;
    JLabel lblTitolo;
    JTextField ed_dato_campo;

    pane.setLayout(new GridBagLayout());
    GridBagConstraints c = new GridBagConstraints();
    c.fill = GridBagConstraints.HORIZONTAL;
    c.anchor = GridBagConstraints.PAGE_START;

    lblTitolo = new JLabel("Button 1");
    lblTitolo.setFont(new Font("Arial", Font.PLAIN, 16));

    c.weightx = 0.5;
    c.gridx = 0;
    c.gridy = 0;
    pane.add(lblTitolo, c);

    ed_dato_campo = new JTextField("Button 2");
    ed_dato_campo.setFont(new Font("Arial", Font.PLAIN, 20));
    c.gridx = 0;
    c.gridy = 1;
    pane.add(ed_dato_campo, c);

    button = new JButton("Button 3");
    c.gridx = 1;
    c.gridy = 1;
    pane.add(button, c);

    button = new JButton("Long-Named Button 4");
    c.ipady = 40;
    c.weightx = 0.0;
    c.gridwidth = 3;
    c.gridx = 0;
    c.gridy = 2;
    pane.add(button, c);
    return pane;
}

enter image description here