Acrylic film, method for producing same, laminate film, laminated injection molded article, and method for producing rubber-containing polymer
An acrylic film having few fish eyes and a method for producing latex of an acrylic rubber-containing polymer having low amounts of coarse particles, excellent filtering properties, and low filter clogging frequency during a filtration step for removing foreign substances are provided. An acrylic film containing an acrylic rubber-containing polymer (G) has a thickness of 30 to 300 μm, wherein the number of fish eyes that are 0.001 mm 2 or greater in size is 130/m 2 or fewer when a section having a light transmission rate of 75% or less for light having a wavelength of 400 to 1100 nm was detected as a fish eye.
1. A method for producing an acrylic rubber-containing polymer (G) used for an acrylic film, the method comprising multi-stage polymerization steps including the following steps (1) and (2):
(1) a first stage polymerization step in which a first emulsion having a monomer mixture (a) containing 20% by mass or more of alkyl acrylate emulsified in water is supplied to a polymerization vessel, and
(2) a second stage polymerization step in which a second emulsion having a monomer mixture (b) containing 50% by mass or more of alkyl methacrylate emulsified in water is supplied to the polymerization vessel after the first polymerization step,
wherein a number average particle diameter of a dispersion phase is 300 μm or less for the first emulsion and the second emulsion, respectively, and
an amount of a surfactant used for preparation of the emulsions is set at 0.5 parts by mass or more and 1.6 parts by mass or less relative to the total amount of 100 parts by mass of a monomer mixture in any polymerization steps of the multistage polymerization steps,
wherein at least one polymerization step (3) is included between the step (1) and the step (2), and the polymerization step (3) does not include an emulsifying step.
2. The method according to claim 1 , wherein the number average particle diameter of a dispersion phase is 200 μm or less for the first emulsion and the second emulsion, respectively.
3. The method according to claim 1 , wherein the number average particle diameter of a dispersion phase is 100 μm or less for the first emulsion and the second emulsion, respectively.
4. The method according to claim 1 , wherein the number average particle diameter of a dispersion phase is 0.1 μm or more for the first emulsion and the second emulsion, respectively.
5. The method according to claim 1 , wherein the first emulsion having the monomer mixture (a) contains 30 to 99.9% by mass of alkyl acrylate emulsified in water.
6. The method according to claim 1 , wherein the second emulsion having the monomer mixture (b) contains 60 to 100% by mass of alkyl methacrylate emulsified in water.