JPH04236255A - Antistatic methacrylic resin composition - Google Patents

Abstract

PURPOSE:To provide the subject methacryl resin composition excellent in antistatic properties by blending a methacryl resin with a polyether ester amide. CONSTITUTION:A composition composed of [I] 70-98 pts.wt. methacryl resin containing >=70wt.% methyl methacrylate unit and [II] 30-2 pts.wt. (100 pts.wt. in total) polyether ester amide. The methacryl resin composition excellent in antistatic properties and capable of water washing without reduction of its performance can be obtained.

Description

[Detailed description of the invention]

0001

0001

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a methacrylic resin composition having excellent antistatic properties.

0003

0002

0004

[Prior art] Methacrylic resin has excellent transparency and
Due to its good mechanical properties and workability, it is widely used in lighting equipment, signboards, and various decorative items. However, since the surface resistivity is very high, dust and the like easily adhere to the resin surface and make it dirty, and an improvement is desired.

[0005]

[0003] Conventionally, in order to improve the antistatic performance of such methacrylic resins, it has been necessary to coat silicone compounds, incorporate various surfactants, fatty acid esters of polyhydric alcohols, or compounds having sulfonic acid groups. A method has been proposed.

[0006]

0004

[0007]

[Problems to be Solved by the Invention] However, methods using silicon compounds are generally expensive and therefore extremely disadvantageous in terms of cost, and methods using surfactants are not sufficiently effective for practical use. Not obtained. On the other hand, in the method of kneading fatty acid ester, no effective improvement in antistatic ability is observed with the usual common sense addition amount, and it is unavoidable to add a large amount of fatty acid ester. In this case, there is a problem in that the heat resistance of the obtained resin is significantly reduced, which greatly limits the molding process.

[0008]

[0005] Furthermore, the method of adding a compound having a sulfonic acid group shows a remarkable improvement in antistatic ability, but there remains a problem with its permanence, as the effect is significantly reduced by one-time washing with water. As described above, although many various measures have been taken to prevent electrification of methacrylic resin, no effective solution has yet been found.

[0009]

[0006]

0010

[Means for Solving the Problems] Therefore, as a result of intensive studies in view of the current situation, the present inventors found that by blending polyether ester amide with methacrylic resin,
The present inventors have discovered that it is possible to obtain a methacrylic resin composition that maintains moldability without impairing heat resistance and has excellent permanent antistatic properties, and has completed the present invention.

[0011]

That is, the present invention provides a methacrylic resin [I] 70-9 having 70% by weight or more of methyl methacrylate units.
8 parts by weight and polyether ester amide [II] 3
This is an antistatic methacrylic resin composition containing 0 to 2 parts by weight (100 parts by weight in total).

0012

The methacrylic resin [I] of the present invention has methyl methacrylate units in an amount of 70% by weight or more, and other monomers copolymerizable with methyl methacrylate include ethyl methacrylate, butyl methacrylate, and methacrylate. Methacrylic acid alkyl esters such as cyclohexyl acrylate; Acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; Aromatic vinyl compounds such as styrene, vinyltoluene, and α-methylstyrene; Acrylonitrile, methacrylonitrile, etc. Vinyl cyanide monomers; acid anhydrides such as methyl cinnamate, methyl crotonate, and maleic anhydride; maleimides such as N-phenylmaleimide, N-(O-chlorophenylmaleimide), N-ethylmaleimide, and N-cyclohexylmaleimide These can be used alone or in combination of two or more. Furthermore, resins obtained by imidizing these resins by an imidization reaction, or resins obtained by rubber modification can also be used.

[0013]

The methacrylic resin [I] is used in an amount of 70 to 98 parts by weight based on 100 parts by weight of the resulting resin composition.
If it is less than 70 parts by weight, the decrease in mechanical strength is relatively large;
On the other hand, if it exceeds 98 parts by weight, antistatic properties will not be exhibited, which is not preferable.

[0014] The methacrylic resin [II] is heated at 25°C.
The intrinsic viscosity [η] measured in chloroform is 0.03
The range of 0.1 to 0.1/g is preferable.

[0015]

Next, the polyether ester amide [II] used in the present invention is (a) an aminocarboxylic acid lactam having 6 or more carbon atoms such as 11-aminoundecanoic acid and caprolactam, or hexamethylene diamine-adipic acid. salts and salts of diamines and dicarboxylic acids having 6 or more carbon atoms such as hexamethylene diamine sebacate; (b) poly(ethylene oxide) having a number average molecular weight of 200 to 6,000 such as
(ethylene oxide) glycol and (C) dicarboxylic acid having 4 to 20 carbon atoms, such as terephthalic acid or isophthalic acid, and refers to a polyether ester unit containing 95 to 10% by weight.

[0016]

The antistatic ability of this polyether ester amide [I] improves as the amount added increases, but 3
If more than 0 parts by weight is added, the heat distortion temperature will drop significantly. In addition, if a small amount of less than 2 parts by weight is added, effective antistatic ability cannot be obtained. Therefore, in consideration of the appearance and processability of the molded product, it is desirable to add 2 to 30 parts by weight.

[0017]

In order to produce the methacrylic resin composition of the present invention, polyether ester amide [II] is mixed with methacrylic resin [I], and the mixture is melt-mixed using an extruder and then formed into pellets. is preferable.

[0018]

[0013]

[0019]

[Examples] The present invention will be specifically explained below with reference to Examples. Note that "%" and "parts" in the examples indicate "% by weight" and "parts by weight", respectively.

[0020]Measurement of each physical property value was carried out by the following method.

[0021] Total light transmittance Measured according to ASTM-D1003.

[0022] Heat distortion temperature Measured according to ASTM-D648.

Surface specific resistance value 1) Immediately after injection molding, the molded plate was left in a constant temperature room at 23°C and 50% humidity for 24 hours, and then measured using a super insulation resistance meter (manufactured by Advantest Co., Ltd., TR-8601). . After the measurement, the sample was thoroughly washed with distilled water to remove moisture from the surface, and then left in a constant temperature room at 23° C. and 50% for 24 hours and measured again.

2) After the operation in 1), the molded plate was heated at 23°C and 50°C.
% humidity for 100 days, and then measured using the same super insulation resistance meter.

[0025]

Production of methacrylic resin [I] 100 parts of a monomer prepared by mixing 97 parts of methyl methacrylate and 3 parts of methyl acrylate with 0% of n-octyl mercaptan.
．． 0.1 part of azobisisobutyronitrile as a polymerization catalyst, 0.1 part of stearyl alcohol as a mold release agent, and methyl methacrylate and potassium 3-methacryloyloxypropanesulfonate as suspension polymerization dispersants. 0.01 part of the copolymer, 0.15 parts of sodium sulfate, and 145 parts of water were mixed into a glass flask polymerization apparatus equipped with a stirrer and a thermometer, and polymerized at 80°C. After the internal temperature reached a peak, the mixture was heated to 95°C. After holding for 30 minutes, the mixture was cooled, filtered, washed with water, and dried to obtain a beaded methacrylic resin.

[0026]

Examples 1 to 4 Methacrylic resin [I] and polyether ester amide [II] (manufactured by ATOCHEM Co., Ltd.: Pebax (R) 4011MA00) in the proportions shown in Table 1 were stirred and mixed.
After kneading and pelletizing using an mφ extruder, a flat plate of 100×100×2 mm was produced at 250° C. using an injection molding machine. The total light transmittance, heat deformation temperature, and surface resistivity of the obtained molded plate were measured. The results are shown in Table 1.

[0027]

Comparative Example 1 An experiment was conducted in the same manner as in the example using only methacrylic resin [I] without adding polyether ester amide. The results are shown in Table 1.

[0028]

Comparative Example 2 An experiment was conducted in the same manner as in the example except that 2 parts of sodium dodecylbenzenesulfonate was added to 98 parts of methacrylic resin [I]. The results are shown in Table 1.

[0029]

Comparative Example 3 An experiment was conducted in the same manner as in Example except that 7 parts of stearic acid monoglyceride was added to 93 parts of methacrylic resin [I]. The results are shown in Table 1.

[0030]

[0019]

[0031]

[Table 1]

[0032]

From the results in Table 1, it can be seen that all of the resin compositions of the present invention exhibit good antistatic properties and are permanent without changing due to surface washing with water or changes over time. Furthermore, it can be said that molding is possible without a decrease in heat deformation temperature.

[0033]

[0021]

[0034]

Effects of the Invention The methacrylic resin composition of the present invention has excellent antistatic ability and does not lose its performance even when washed with water, so it exhibits excellent industrial effects.

Claims (1)

[Claims] Claim 1: An antistatic methacrylic resin comprising 70 to 98 parts by weight of methacrylic resin [I] having 70% by weight or more of methyl methacrylate units and 30 to 2 parts by weight of polyether ester amide [II] (100 parts by weight in total). Composition.