Philippine Tourist Applying for China Visa in Singapore

Hi! I am Filipino with Philippine passport. My husband & I are visiting our son & his family in Singapore. They are transferring to Shanghai to work, just waiting for their working visas.

Can we apply for L visa from Singapore so we can accompany them during their transfer? We have another son presently working in Shanghai who can give us an invitation letter. I go to Shanghai every year.... I have several visa stickers in my passport.

We did not get our visas in the Philippines because we plan to file our applications here in Singapore. Will we be able to do this?

Thanks.