JPS633885B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention produces a butadiene polymer in a system consisting of α-methylstyrene, butadiene, and alkyl lithium, then converts it into a latex, and then polymerizes an aromatic vinyl compound and a polar vinyl compound to produce an impact-resistant product with improved heat resistance. The present invention relates to a method for producing a synthetic resin. Conventionally, so-called ABS resin, which is made by polymerizing acrylonitrile, styrene, etc. in the presence of butadiene polymer latex, has been known as a resin with good impact resistance, but this butadiene polymer latex was manufactured using a solution polymerization method. A method has been proposed in which a butadiene polymer is dissolved in an organic solvent such as toluene and then made into a latex using an emulsifier in the presence of an emulsifier. However, this method requires a step of removing the organic solvent after forming a latex, which is a complicated operation, and has the serious drawback that the latex often aggregates during solvent removal, deteriorating the physical properties of the final polymer. There is. In order to overcome these drawbacks, the present inventor has conducted intensive studies on a method for producing a butadiene polymer latex based on a solution polymerization method without using substantially organic solvents, and as a result, an organic solvent is not required in the latexization process. Furthermore, we have discovered a method for producing impact-resistant resins with improved heat resistance (heat distortion temperature). That is, the present invention provides α
-Mole ratio of methylstyrene and butadiene is 10~
Adjust to 80/90~20 and add 0.01~0.5 parts by weight of alkyl lithium to 100 parts by weight of the adjusted product to 30~150.
0.5 to 15 parts by weight of an emulsifier and 100 to 1000 parts by weight of water as a dispersant are added to 100 parts by weight of a butadiene polymer obtained by carrying out the reaction at a temperature of 100°C until the polymer reaches a high degree of polymerization. By obtaining a polymer latex, adding an aromatic vinyl compound, a polar vinyl compound, and a polymerization catalyst to the latex and causing a polymerization reaction to occur.

[Table] Polar vinyl compounds (d)〓
(Here, (b + c): (d) = 80-20: 60-40 mol%, (b): (c) = 95-15: 5-85 mol%)
Provided is a method for producing an impact-resistant resin with improved heat resistance. The present invention will be explained in detail below. The butadiene polymer of the present invention is prepared by adjusting the molar ratio of α-methylstyrene and butadiene to 10 to 80/90 to 20, and adding alkyl lithium (preferably normal butyl lithium, secondary butyl lithium, or ethyl lithium) to 100% by weight of the adjusted product. 0.01~
It is obtained by adding 0.5 parts by weight and carrying out the reaction at a temperature of 30 to 150°C until the polymer has a high degree of polymerization.
Since this polymerization reaction is a so-called bulk polymerization that does not substantially use a solvent, it is desirable to remove the generated polymerization heat by jacket cooling or by a so-called overhead cleaning method that utilizes the heat of evaporation. In addition, there is no problem in carrying out the present invention if the alkyllithium catalyst is diluted with a small amount of an organic solvent that does not contain water or the like. Although it is acceptable for a small amount of α-methylstyrene to be included in the butadiene polymer, the content is preferably 10% by weight or less. The resulting mixture of butadiene polymer and unreacted α-methylstyrene is subjected to a latexing step. Latex formation can be easily achieved by a conventional method, but by adding 0.5 to 15 parts by weight of an emulsifier such as a rosinate salt and 100 to 1000 parts by weight of water as a dispersant to 100 parts by weight of the butadiene polymer, using a homomixer, A butadiene polymer latex can be stably obtained using an emulsifying machine such as a homogenizer, disper mill, or colloid mill. In order to further improve the impact resistance of the final polymer, the latex can be treated to increase the degree of gelation of the rubber component. Examples of aromatic vinyl compounds that undergo polymerization in the butadiene polymer latex thus obtained include styrene, vinyltoluene, vinylxylene, chlorostyrene, dichlorostyrene, paratertiary butylstyrene, vinylnaphthalene, etc. Styrene is particularly suitable. Also,
As the polar vinyl compound, acrylonitrile, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl methacrylonitrile, etc. are preferably used. These aromatic vinyl compounds and polar vinyl compounds are

[Table] Polar vinyl compounds (d)〓
(Here, (b + c): (d) = 80-20: 60-40 mol%, (b): (c) = 95-15: 5-85 mol%)
The composition is adjusted to be . Furthermore, the polymerization catalyst for aromatic vinyl compounds and polar vinyl compounds is not particularly limited, and radicals such as persulfate-based (e.g. potassium persulfate) or redox-based (cumene hydroperoxide/ferrous sulfate) etc. A catalyst is shown as a representative example. The polymer produced in this way undergoes normal coagulation and
After a drying process, it is recovered as a powdered polymer. The physical properties of the polymer obtained by the present invention are that it has excellent impact resistance and improved heat resistance. That is, while the heat distortion temperature (HDT) of ordinary ABS resin is approximately 90°C, the polymer produced by the method of the present invention has a heat distortion temperature of 91 to 115°C, depending on the content of α-methylstyrene. shows. Therefore, the resin produced according to the present invention is
Like ABS resin, it has a wide range of uses, including pipes, automobile parts, electrical products, and household goods, but it is especially suitable as a material in fields where it takes advantage of its property of being resistant to thermal deformation at high temperatures. This will be explained in more detail below using Examples. In addition, in the examples, parts indicate parts by weight. Example 1 150 parts of butadiene, 200 parts of α-methylstyrene, and 0.05 part of n-butyllithium were charged into a pressure-resistant reactor equipped with a cooling device and reacted at 70° C. for 1.5 hours.
After the reaction, add 2 parts of sodium rosin acid to a mixture of 102 parts of butadiene polymer and unreacted α-methylstyrene, etc.
1 part, and 200 parts of an aqueous solution containing sodium carbonate in an equimolar amount to sodium rosinate were mixed and emulsified in a disper mill. Take 15 parts of the above latex as solid rubber,
Add to this 30 parts of styrene, 25 parts of acrylonitrile, 0.1 part of dodecyl mercaptan, and 0.5 parts of potassium peroxide.
After adding 0.5 parts of potassium oleate and reacting at 50°C for 6 hours, the reaction product was coagulated with dilute brine and sulfuric acid, and the polymer was recovered. The physical properties of the obtained polymer were as follows. Izot and impact value (measured according to ASTMD-256) (ft-lb/inch with notch) 5 Rockwell hardness (measured according to ASTMD-785)
100 Tensile strength (PSi) (measured by ASTMD-636) 5900 Heat distortion temperature (℃) (measured by ASTMD-648)
94 Example 2 The process of producing a butadiene polymer in Example 1 was carried out under exactly the same conditions except that 150 parts of butadiene, 250 parts of α-methylstyrene, and 0.6 parts of n-butyllithium were used, and the Izod impact value was 5.2. A polymer having a heat distortion temperature of 101°C in ft-lb/inch was obtained. Example 3 Performed under exactly the same conditions as in Example 1 except that methyl methacrylate was used instead of AN,
Izotsu impact value 4.4ft-lb/inch, heat distortion temperature
A polymer at 93.5°C was obtained.

Claims (1)

[Claims] 1 Substantially without using a solvent, α-methylstyrene and butadiene are adjusted to a molar ratio of 10 to 80/90 to 20, and alkyl lithium is added to 0.01 to 100 parts by weight of the prepared product. Add 0.5 parts by weight of emulsifier to 100 parts by weight of butadiene polymer obtained by reacting at a temperature of 30 to 150°C until the polymer reaches a high degree of polymerization.
By adding 0.5 to 15 parts by weight and 100 to 1000 parts by weight of water as a dispersant to obtain a butadiene polymer latex, and adding an aromatic vinyl compound, a polar vinyl compound, and a polymerization catalyst to the latex to perform a polymerization reaction. [Table] Polar vinyl compounds (d)〓
(Here, (b + c): (d) = 80-20: 60-40 mol%, (b): (c) = 95-15: 5-85 mol%)
A method for producing an impact-resistant resin with improved heat resistance having a composition comprising: