For example, if the slogan is for a laptop case that protects Mac laptops, could you trademark "Protect your Mac's back".
No, you cannot use another's trademark as part of any mark that identifies your goods or services.
I strongly advise that you do not waste your time trying to accomplish this on your own as there is a lot more to the process than you might realize and you really do not want to waste your money on fees.
Further, whenever you endeavor into investing in a trademark it is very important that you conduct the proper clearance due diligence upfront and before you submit an application to the USPTO. In the US, this means searching under both federal (USPTO) as well as common law because trademark rights stem from use in this country NOT registration. This means that acquiring a federal registration does not necessarily mean that you are not infringing on another's intellectual property. See the link below for a detailed explanation of the due diligence process.
I suggest that you consult with a lawyer in private and discuss your objectives in more detail. You can start by calling around to several for a free phone consultation, get some insights then pick the best fit to work with.
DISCLAIMER: this is not intended to be specific legal advice and should not be relied upon as such. No attorney-client relationship is formed with the law firm of Natoli-Lapin, LLC on the basis of this posting.
Intellectual Property Law Attorney
The short answer is very, very likely not -- assuming that the other company's name is used as the company's name, and not as a reference for something else.
Unlawful: "Cleans Nike Shoes Like New"
Lawful: "Goddess Nike Celebrates Your Victory Over Split Ends"
Before you adopt a slogan as a trademark you need to speak with your own trademark attorney. Good luck.
The above response is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.
I would agree with my colleagues. I think there is a difference between what you seek to do, and nominative use, e.g. advertising that you repair Macs, (without implying certification, implied endorsement and other issues.".
Further, the slogan is not trademarked; unless it is the name of the product or service in commerce and identifies the source of the goods or services.
The above is general legal and business analysis. It is not "legal advice" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.
Intellectual Property Law Attorney
No, I don't think that works. First off, your example is not a trademark it is merely an advertising slogan. If you use it as a trademark it will be an ill legal infringement of the famous MAC trademark of Apple Computer. You need another name for your product other than a slogan and that other name would be the trademark to the extent you use it in commerce and/or apply to register it. For example, you might brand this laptop case as the the "FLIP-FLOP" laptop case and then advertise "protect your Mac's back with our FLIP-FLOP laptop case" and then somewhere put a disclaimer that Mac is a trademark of Apple Computer with which you are not affiliated in any way.
What you really need to do is see an IP lawyer so you get this right as you have a number of misunderstandings about trademark law and correct trademark use.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.