JPS6326125B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing an acrylic thermoplastic resin having antistatic properties. Acrylic resins are known for their outstanding transparency, good mechanical properties, workability, and beautiful molded products, and are widely used in lighting equipment, signboards, various decorative items, nameplates, and the like. However, because the surface resistivity is extremely high, it is difficult for static electricity induced by contact or friction to dissipate, and as a result, the resin surface during use is easily contaminated by dust, etc., spoiling its beautiful appearance. This is the result. Conventionally, antistatic methods for synthetic resins are roughly divided into additive kneading methods using surfactants and surface coating methods using silicone compounds. Regarding the additive kneading type, it has been proposed to add fatty acid esters of polyhydric alcohols, etc., but it has almost no effect, or if it is effective, it does not improve the colorless transparency and surface gloss characteristic of acrylic resins. Either the quality of the molded product is significantly reduced and it cannot be put to practical use, or the antistatic agent bleeds onto the surface of the molded product, significantly inhibiting secondary processability such as printing and painting. In addition, although some surface coating types have been put into practical use, they require a step of applying an antistatic agent to the final product, which poses a problem in terms of cost. Therefore, in order to eliminate the above-mentioned drawbacks, the present inventors conducted intensive studies on acrylic copolymers of acrylic monomers and copolymerizable monomers, and as a result, unexpectedly, a certain acrylic copolymer was found. The inventors have discovered that it exhibits good antistatic performance and is excellent in suitability for printing and coating, leading to the present invention. That is, the present invention provides 75% or more of methyl methacrylate and/or ethyl methacrylate,
1 part of a monomer () containing 25% or less of one or more of methyl acrylate, ethyl acrylate, butyl acrylate, styrene, acrylonitrile, and the general formula (In the formula, n is an integer of 2 to 12, R is a carbon number of 2 to 4
represents a hydrocarbon group. This is a method for producing an acrylic thermoplastic resin having antistatic ability, which comprises copolymerizing 0.01 to 0.15 parts of the monomer ( ) represented by the following formula. The acrylic monomer () of the present invention includes:
Methyl methacrylate and/or ethyl methacrylate, and one or more mixtures of methyl acrylate, ethyl acrylate, butyl acrylate, styrene, acrylonitrile in an amount of up to 25% based on the above monomers, preferably methyl methacrylate 75 ~99
%, methyl acrylate or ethyl acrylate can be used. In addition, monomers () copolymerizable with the above monomers include the general formula (In the formula, n is an integer of 2 to 12, R is a carbon number of 2 to 4
represents a hydrocarbon group. ) A polyalkylene glycol monomethacrylate represented by the following can be used, and preferably a polyalkylene glycol monomethacrylate in which R is an ethyl group, a propyl group, or a butyl group. The present invention can exhibit its effects when the ratio of monomer () to monomer () is from 1:0.01 to 1:0.15, particularly preferably from 1:0.02 to 1:0.10. 1:0.01
If the monomer () is less than , there is no antistatic effect. When the amount of monomer () is more than 1:0.15, the heat deformation resistance temperature decreases significantly and it cannot be put to practical use. In addition, in the present invention, other additives such as antioxidants, lubricants, ultraviolet absorbers, plasticizers, and various pigments may be added to the composition, if necessary. The method for producing the acrylic resin composition having antistatic ability according to the present invention includes monomer [],
There is a method in which the monomer [] and other additives are mixed and dissolved in advance to form a monomer phase, and then polymerized using a polymerization initiator in a conventional manner.Other methods include adding each component continuously to the polymerization system. A method of continuous polymerization is also possible. Molded products obtained using the resin composition produced in the present invention can be used for meter covers, nameplates, electrical equipment parts, etc., and can exhibit excellent antistatic effects, and can also be used in nameplates, etc. It also has excellent secondary processing properties such as printing and painting. Next, the present invention will be explained in more detail with reference to Examples. Example 1 3 parts of polyethylene glycol monomethacrylate (molecular weight 270) was added to 97 parts of methyl methacrylate, dissolved at 23°C, and then 0.08 part of azobisisobutyronitrile and stearyl alcohol were added.
0.1 part (mold release agent) was added and mixed. The mixture thus obtained was poured into a polymerization cell consisting of a vinyl chloride gasket and two glass plates, polymerization was carried out at 80°C for 3 hours, and then aged at 110°C for 1 hour. The obtained resin plate was conditioned in a constant temperature room for one day and night, and its antistatic ability was measured. The results are shown in Table 1. The antistatic performance is clear by comparing with Comparative Example 1. Examples 2 to 4, Comparative Examples 1 to 3 Polymerization was carried out in the same manner as in Example 1, except that monomers () and monomers () were blended as shown in Table 1, and the resulting resin plates were evaluated. The results are shown in Table 1.

[Table] Reference Example 1 88 parts of methyl methacrylate, 2 parts of methyl acrylate, 10 parts of an equimolar mixture of glycerin monostearate and boric acid were mixed and dissolved, and 0.05 part by weight of azobisisobutyronitrile was added. Using the mixture thus obtained, a resin plate was obtained in the same manner as in Example 1. Surface resistivity is 2.0×10 ¹¹ ,
The charge decay half-life was 4 seconds, but the printability was poor.

Claims (1)

[Claims] 1 75% or more of methyl methacrylate and/or ethyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate,
1 part of a monomer () containing 25% or less of one or more of styrene and acrylonitrile, and the general formula (In the formula, n is an integer of 2 to 12, R is a carbon number of 2 to 4
represents a hydrocarbon group. 1. A method for producing an acrylic thermoplastic resin having antistatic properties, which comprises copolymerizing 0.01 to 0.15 parts of a monomer () represented by the following formula.