Claims
- 1. A polymer product which is a core/shell impact modifier produced by a process which comprises:
- a. polymerizing in emulsion, in a pressure vessel, a first mixture of monomers, comprising at least 40% butadiene, and further comprising at least one polyunsaturated monomer for controlling the crosslinking of the polybutadiene, in the presence of an emulsifier and a free-radical initiator,
- b. adding an agglomerating agent after 60%-90% conversion of the first mixture of monomers to polymer having a particle size of 70-110 nm,
- c. continuing the polymerization until 60%-90% conversion of the monomers to polymer and a particle size of 120-240 nm. have been achieved;
- d. continuing the polymerization of the first mixture of monomers while adding a second mixture of monomers which mixture comprises at least one of a C.sub.1 -C.sub.4 alkyl methacrylate, and
- e. continuing the polymerization of the second mixture of monomers to at least 80% conversion to polymer.
- 2. A polymer product which is a core/shell impact modifier produced by a process which comprises:
- a. polymerizing in emulsion, in a pressure vessel, a first mixture of monomers, comprising at least 40% butadiene, and further comprising at least one polyunsaturated monomer for controlling the crosslinking of the polybutadiene, in the presence of an emulsifier and a free-radical initiator, until 60%-90% conversion of the monomers to polymer and a particle size of 120-240 nm. have been achieved;
- b. continuing the polymerization of the first mixture of monomers while adding a second mixture of monomers which mixture comprises at least one of a C.sub.1 -C.sub.4 alkyl methacrylate or a vinyl aromatic monomer;
- c. continuing the polymerization of the second mixture of monomers to at least 80% conversion to polymer;
- d. during or after step (c), beginning addition of a third mixture of monomers, which mixture comprises at least one of a C.sub.1 -C.sub.4 alkyl methacrylate or a vinyl aromatic monomer; and
- e. continuing the polymerization to 60-100% conversion of all monomers present from the second and third monomer mixtures to polymer.
- 3. polymer product of claim 2 wherein an agglomerating agent is added during step (a) after 60%-90% conversion of the first mixture of monomers to polymer having a particle size of 70-110 nm.
- 4. The polymer product of claim 2 or claim 3 wherein steps (b) to (e) are repeated one or more times.
- 5. The polymer product of claim 1 wherein steps (d) and (e) are repeated one or more times.
- 6. A thermoplastic blend of a matrix polymer selected from poly(vinyl chloride), poly(methyl methacrylate), a poly(alkylene terephthalate), polyacetal, polycarbonate, and mixtures thereof with from 2 to 40 parts, based on 100 parts of the matrix polymer, of the polymer product produced by any of the processes of claims 1, 2, 3, 4, or 5.
- 7. An article formed from the blend of claim 6.
Parent Case Info
This is a divisional of application Ser. No. 08/349,645, filed Dec. 5, 1994, U.S. Pat. No. 5,534,594.
US Referenced Citations (13)
Foreign Referenced Citations (2)
Number |
Date |
Country |
3100011 |
Apr 1991 |
JPX |
1103243 |
Jul 1964 |
GBX |
Non-Patent Literature Citations (1)
Entry |
189005 Dec. 20, 1979 Research Disclosure. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
349645 |
Dec 1994 |
|