Product share virtual store for Facebook

I'm having trouble to make the share of a product from a virtual store for facebook. I'm putting the meta tags on the product page:

<meta property='og:title'...
<meta property='og:url' ...
<meta property='og:site_name' ...
<meta property='og:type' content='website'/>
<meta property='og:image' ...    
<meta property='og:description' ...

And the script I use to open the share window is as follows:

$("#btn_facebook").bind('click', function (event) {
      var twtTitle = document.title;
      var twtUrl = location.href;
      var imagem = 'http://ift.tt/1f2izrE' + $("#Share_Image").val();
      var twtLink = 'http://ift.tt/ML4eCW' + twtUrl;
      window.open(twtLink,'', '_blank', 'location=no, menubar=no, resizable=yes, width=575, height=520, fullscreen=yes, status=no, titlebar=no, toolbar=no');                                    
});

To open the share window properly with the photo and description of the product, but when I click share, in posting on facebook, go all descriptions and text, But the image does not load and does not appear.

It appears only a whiteboard without the photo that appeared before.

Can anyone help me identify this problem or have any solutions?

Thanks, Alex