JPS6059256B2 - Methacrylic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a methacrylic resin composition that exhibits little coloration, high transparency, and excellent moldability under thermoplastic resin molding conditions.

Conventionally, methacrylic resins have been processed and molded by extrusion molding or injection molding in addition to cast molding, but molding conditions are required that do not impair the colorless transparency, which is a characteristic of the resin.

Generally, in the case of extrusion or injection molding of thermoplastic resins, lubricants are added to facilitate the molding process, and for methacrylic resins, higher alcohols, higher fatty acids and their derivatives fatty acid amides, esters, etc. , metal soap, etc. are used.

However, when applying these lubricants to methacrylic resin,
Since the molded product becomes colored and its colorless transparency is impaired, the amount of lubricant added is severely limited, and the lubricant has the disadvantage that the effect of the lubricant on molding processability is not fully demonstrated. .

As a result of a detailed study of the influence of these lubricants on colorless transparency and the relationship between the lubricating effect, the present inventors found that there was a surprising synergistic effect between fatty acid amide and metal soap, and the above drawbacks could be significantly improved. discovered a lubricant that could be used as a lubricant, and completed the present invention. That is, the present invention provides general formula RICONH(CH2)nNHCOR1 of the following (I) or (■)...
I) R1CONH2... (■) (However, R1
is an alkyl group having 7 to 21 carbon atoms, n is an integer of 1 to 6), and at least one aliphatic amide represented by the following general formula (■): R, COO)mM...(■) (However, R,
has the same meaning as above, M is a metal of Groups 1 to 2 of the periodic table, m is a number less than or equal to the maximum valence of M), and the ratio of one to the other is 20 to 8. The gist thereof is a methacrylic resin composition, characterized in that the total amount of both is within the range of 0.002 to 0.2 parts by weight based on 100 parts by weight of the methacrylic resin. It is something to do.

As a method for producing the compounded composition of the present invention, a method is adopted in which a mixture of fatty acid amide and fatty acid metal soap is added during production of methacrylic resin. Torque during kneading can be reduced.

The blending ratio of at least one fatty acid amide selected from general formulas (1) and (■) used in the present invention and the metal soap (■) is 20 to 80% by weight of the other. It is most desirable to mix at around 1:1.

Outside the above range, no sufficient synergistic effect will be exhibited, and only approximately the same effect as when each is added alone can be expected. The amount of the mixture of the fatty acid amide and metal soap of the present invention added to the methacrylic resin is 0.00 parts per 10 weight parts of the resin.
002 to 0.2 parts by weight, preferably 0.005 to 0.005 parts by weight
If the amount added to the resin is 0.1 part by weight or less, the lubricity effect is particularly insufficient, and if it is 0.2 part by weight or more, the lubricity effect corresponding to the amount added cannot be obtained. Not only that, but depending on the quality of the fatty acid amide or metal soap, the molded product may be colored, which is undesirable as it may affect the transparency. The methacrylic resins used in the present invention include (a), (c), (c), (ii) and (e) below.
At least one type of homopolymer or a mixture of a homopolymer and a copolymer selected from the following can be mentioned. (a) Homopolymer of methyl methacrylate (b) Methyl methacrylate (hereinafter referred to as MMA). A copolymer of acrylic acid ester such as methyl alcohol, ethyl alcohol, butyl alcohol, propyl alcohol, etc.

(c) A copolymer of MMA and a vinyl monomer such as acrylonitrile or styrene.

((d) Copolymer of MMA, acrylic ester (same as above), and vinyl monomer (same as above).

(e) Copolymer of acrylic ester and vinyl monomer (same as above).

The above general formulas (1), (■) and (■) used in the present invention
The number of carbon atoms in the alkyl group (R1) of the compound represented by ) is 7 to 21, and those having 11 or more carbon atoms are particularly preferable because they cause less loss on heating under the heating conditions during molding.

Those having 6 or less carbon atoms have a small lubricating effect on methacrylic resin and also have low thermal stability, so they do not give favorable results. Furthermore, if the number of carbon atoms is 22 or more, the lubricating effect will decrease. For example, the compound (1) includes lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, etc., and the compound (■) includes methylene bis stearic acid amide, ethylene bis stearic acid amide,
Examples include hexamethylene bisstearamide.

In addition, the compound (■) includes Li salt, Ca salt, Ba salt, Zn salt, Cd salt, A of stearic acid or lauric acid, etc.
1 salt, Pb salt, etc., and any metal soap may be used as long as the number of fatty acids bonded to the metal is less than or equal to the maximum valence of the metal atom, and there are no restrictions on its properties. It is desirable that the methacrylic resin does not contain any insoluble substances when melted so as not to impair the transparency of the methacrylic resin. It is unclear why the combination of at least one selected from compounds (1) and (■), which is the gist of the present invention, and compound (■) exerts a remarkable effect on methacrylic resin, but the present invention Compared to the case where the known lubricants (1), (■), and (■) are added alone, the composition not only suppresses the coloring of the molded product and maintains colorless transparency, but also reduces the amount added. can be increased, and workability is significantly improved.

Furthermore, as shown in the examples, the composition of the present invention includes (1),
Compared to when (■) and (■) are added alone to methacrylic resin, the moldability is improved, especially the torque during kneading is significantly reduced, and the power load required for kneading is reduced. There are benefits.

Further, when considering the remarkable effects of improving colorless transparency and reducing torque during kneading according to the present invention, it is recognized that the two are related to each other and have a mutual effect.

In addition, the methacrylic resin composition of the present invention contains antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, flame retardants, etc., which are usually added to exhibit other effects, to color molded products. They may be added in combination as long as they do not advance the process or impede transparency.

The present invention will be further explained below with reference to examples, but the present invention is not limited to the following examples.

In addition, all parts in the examples indicate parts by weight. Example 1 The ratios (parts: parts) of ethylene bisstearamide (manufactured by Nippon Kasei Co., Ltd.) and barium stearate (manufactured by Sakai Chemical Co., Ltd.) were 100:0, 70:30, and 50:5013, respectively.
Mix so that the ratio is 0:70 and 0:100, and the 0.屹BE was added (sprinkled) to 1 (1) part each of pellets of methacrylic resin (Acrypet manufactured by Mitsubishi Rayon Co., Ltd.),
A portion of the mixture was mixed with a 45 r.p. p. 230°C at a rotational speed of m, 1
Kneaded in between.

The resin after kneading is injected into the mold, defoamed with a hot press, then transferred to a cold press. A thick molded plate was obtained. In the same manner, molded plates of 5 sequential thicknesses were made using methacrylic resin alone.

The transmittance (420 nm) in the thickness direction was measured at eight arbitrary locations on the molded plate (100Tr$TXlO-X5), and the average value was determined. Also, record the torque curve during kneading with the plasticorder, and 1 from the time when the torque reached the maximum value.
It was determined by comparing the torque comparison value and the integral value per minute (the value when methacrylic resin was kneaded alone was 100
).

The transmittance values and torque comparison values are summarized in Table 1, and the composition of the present invention has a clear additive effect compared to when ethylene bisstearamide and barium stearate are added alone. It was found that the transparency did not deteriorate compared to the blank, and the decrease in torque was extremely large.

Example 2 The ratio (parts: parts) of ethylene bisstearamide and calcium stearate (manufactured by Sakai Chemicals) was 100:
0, 70:30, 50:50, 30:70, 0:100
0.02 part of the mixture was added to each 10(2) of methacrylic resin, and a portion thereof was subjected to the same test as in Example 1.

The results are shown in Table 2, and similar to Example 1, a significant mutual effect was observed. Example 3 The ratio (parts: parts) of stearic acid amide (1) manufactured by Honkasei Co., Ltd.) and barium stearate was 100:0, respectively.
, 70:30, 50:50, 30:70, and 0:100. The top part is made of methacrylic resin 10
The test was carried out in the same manner as in Example 1, and the results shown in Table 3 were obtained.

Similar to Example 1, a significant mutual effect was observed. Ethylene bisstearamide was mixed with magnesium stearate (manufactured by Sakai Kagaku) and cadmium stearate (manufactured by Eishin Kasei) at a ratio of 50:50 (part: part), and 0.02 part of each was added to 1ω part of methacrylic resin. By adding them, the same procedure as in Example 1 was carried out, and the results shown in Table 4 were obtained in comparison with the case of each alone.

Similar to Example 1, a mutual effect was observed, and the kneading properties were also extremely good. Example 6 Ethylene bisstearamide and barium stearate, each alone or mixed at a ratio of 50:50 (parts: parts), were treated with methacrylic resin 100%.
A test was conducted in the same manner as in Example 1, with the addition levels of 0.02 parts and 0.06 parts per part, and the results shown in Table 5 were obtained.

Claims (1)

[Claims] 1 General formula R_1CONH(CH_2)_nNHCOR_1... of the following (I) or (II)
...(I)R_1CONH_2...(II)
(However, R_1 is an alkyl group having 7 to 21 carbon atoms, and n is an integer of 1 to 6.) and at least one aliphatic amide represented by the general formula (III) below. Metal soap (R_1COO)_mM...
・(III) (However, R_1 has the same meaning as above, M is a metal from Groups I to IV of the periodic table, and m represents a number less than or equal to the maximum valence of M), and the ratio of the two is One is within the range of 20 to 80% by weight relative to the other, and the total amount of both is 0.002 to 0.0% based on 100 parts by weight of the methacrylic resin.
．． A methacrylic resin composition characterized in that the amount is within the range of 2 parts by weight.