add_filter('wp_get_attachment_image_attributes', 'change_attachement_image_attributes', 20, 2);
function change_attachement_image_attributes($attr, $attachment) {
    global $post;
    if ($post->post_type == 'product') {
        $title = $post->post_title;
        $attr['alt'] = $title;
        $attr['title'] = $title;
    }
    return $attr;
}