<?php
function patricks_woocommerce_call_to_order_button(){
	global $product; //get the product object
	if ( $product ) { // if there's a product proceed
		$url = esc_url( $product->get_permalink() ); //get the permalink to the product
		echo '<a rel="nofollow" href="' . $url . '" class="button add_to_cart_button ">Call to order!</a>'; //display a button that goes to the product page
	}
}
add_action('woocommerce_after_shop_loop_item','patricks_woocommerce_call_to_order_button', 10);