JPS59124946A - Heat-resistant methacrylate resin composition - Google Patents

Abstract

PURPOSE:To provide a resin compsn. having excellent transparency and heat resistance, by mixing a methyl methacrylate/alpha-methylstyrene/styrene/maleic anhydride copolymer with a copolymer mainly composed of methyl methacrylate. CONSTITUTION:40-97wt% monomeric or partially polymerized methyl methacrylate (A), 1-20wt% alpha-methylstyrene (B), 1-20wt% styrene or vinyltoluene (C) and 1-20wt% maleic anhydride (D) are mixed together in a ratio of (alpha+beta)/gamma (wherein alpha is a mol no. of component B, beta is that of component C and r is that of component D) of 0.9-1.7. The mixture is polymerized to prepare a copolymer. 1-99wt% said copolymer is mixed with 99-1wt% copolymer contg. at least 80wt% methyl methacrylate to obtain the desired heat-resistant methacrylate resin compsn.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to transparent heat-resistant methacrylic resin compositions.

Methyl methacrylate-based methacrylic resin has excellent optical properties and weather resistance, as well as mechanical properties and
It has relatively well-balanced performance in terms of thermal properties and moldability, so these properties can be used to create products such as signboards, lighting covers, nameplates, automobile parts, electrical equipment parts, decorations, etc. It is widely used in many fields such as miscellaneous goods, and further applications are being developed.

However, because the heat distortion temperature of the negative surface is around 100° C. and the heat resistance is not sufficient, its application is restricted in many fields, and there is a deep-rooted demand for improved heat resistance.

There have already been many proposals for ways to improve the heat resistance of methacrylic resins, such as copolymerization of methyl methacrylate and α-methylstyrene, methyl methacrylate,
A method for copolymerizing α-methylstyrene and maleic anhydride (Japanese Patent Publication No. 49-10156), a method for copolymerizing methyl methacrylate, styrene, and maleic anhydride H (Japanese Patent Publication No. 5.6-43242), methacrylic acid Method for copolymerizing methyl, α-methylstyrene, styrene, and maleic anhydride (%Kaisei 56-s1!122)
, poly-α-methylstyrene to methyl methacrylate Km
A method of polymerizing methyl methacrylate after 1° of solution (Japanese Patent Publication No. 43-1616, Japanese Patent Publication No. 49-8718), a method of copolymerizing methyl methacrylate and N-allyl maleic acid imide (Japanese Patent Publication No. 43-9753) ), a method of copolymerizing methyl methacrylate, α-methylstyrene and maleimide, a method of copolymerizing methyl methacrylate in the presence of a crosslinked polymer using a polyfunctional monomer, a method of copolymerizing methyl methacrylate with methacrylic 111 Polymers copolymerized with methyl methacrylate, α-methylstyrene, and acrylonitrile have been made. However, in the method proposed above, the polymerization rate was extremely low, so the productivity was extremely low and it was not practical.In addition, the mechanical properties, weather resistance, and optical properties were deteriorated, and the molded products were significantly deteriorated. In both cases, heat resistance is improved to a certain extent, but many problems still remain in practical application, such as coloring or poor moldability due to a narrow molding area.

In view of the current situation, the present inventors developed a heat-resistant methacrylic resin that does not reduce the inherent excellent properties of methacrylic resin such as optical properties, mechanical properties, weather resistance, and moldability, and also has excellent productivity. As a result of intensive research, we found that a copolymer having a quaternary copolymer structure of methyl methacrylate-α-methylstyrene-styrene or vinyltoluene-maleic anhydride with a specific composition and methyl methacrylate was combined at 80% by weight. A resin mixture consisting of a copolymer having a copolymer with a content of This discovery led to the present invention.

That is, the gist of the present invention is as follows: (C) Methyl methacrylate or a partial polymer thereof 40-970-97% by weight - methylstyrene 1-20% by weight (C) Styrene or vinyltoluene 1-20% by weight and (D) a copolymer obtained by polymerizing a monomer mixture consisting of 1 to 20% by weight of maleic anhydride (I) containing 1 to 99% by weight of methyl methacrylate and 80% by weight or more of methyl methacrylate ( 6) A heat-resistant methacrylic resin composition comprising 1 to 99% by weight.

The greatest feature of the present invention is that the high refractive index and heat resistant copolymer (1) having the above specific composition and the low refractive index resin whose main component is methyl methacrylate are blended and homogeneously dispersed. , weather resistance and colorless and transparent molded products compared to the ternary and quaternary copolymers described in Japanese Patent Publication No. 49-10156, Japanese Patent Publication No. 56-45242, and Japanese Patent Publication No. 56-81322. It is surprisingly possible to obtain a composition that is extremely well-balanced in properties, fL, heat resistance, and moldability.

The percentage characteristic of the composition of the present invention on bamboo is 105 as the heat distortion temperature.
C. or higher, preferably 115.degree. C. or higher.

In the composition of the present invention, methyl methacrylate or its partial polymer component forming copolymer (1) retains the properties, weather resistance, or mechanical properties inherent to methacrylic resin, and copolymer (6) It is a component to improve compatibility with copolymer (I), and if it is less than 11.40% by weight of 40-970-97 in copolymer (I), the above properties will be lost, and if it exceeds 97% by weight, No improvement in heat resistance can be expected.

In addition, α-methylstyrene, which is a component of copolymer (I), is a component that improves heat resistance and is a component that increases copolymerization reactivity with maleic anhydride. 1 to 20% by weight of medium, 5 to 10% by weight of suitable material
It is. If it is less than 1 flt% (both, it will save in terms of heat resistance) If it exceeds 9.20% by weight, the productivity and the heat decomposition resistance of the copolymer will decrease.

In addition, styrene or vinyltoluene, which is a component of copolymer (1), does not directly improve heat resistance, but indirectly by increasing the copolymerization reactivity of maleic anhydride, which is a heat resistance improving component. It shows a remarkable effect on improving heat resistance and productivity at the same time, and it requires 1 to 20% by weight in the copolymer (1), and if it is less than 1 car mass, it is indirectly Heat resistance decreases and productivity is also inferior. If it exceeds 20% by weight, optical properties and weather resistance will deteriorate. The vinyltoluene used includes ortho-, meta-, and para-substituted vinyltoluenes, and these are used alone or as a mixture of two or more.

Maleic anhydride, which is a component of copolymer (1), is α-
It has the effect of improving the heat resistance of the copolymer through interaction with methylstyrene, styrene or vinyltoluene, and contains 1 to 20% by weight, preferably 5 to 1% by weight in copolymer (I).
5 more weight is required.

If it is less than 1% by weight, productivity and heat resistance will be poor, and boiling resistance will be poor.

In the present invention, considering the overall balance of resin properties such as heat resistance, mechanical properties, optical properties, and moldability of the blend m fat finally obtained, copolymer (I)
), where the number of moles of α-methylstyrene is α, the number of moles of styrene or vinyltoluene is β, and the number of moles of maleic anhydride is γ, the blending ratio of each component (α+β/γ) is 0.
It is most desirable to configure the quantitative relationship to be 9 to t7. When it is less than 0.9, there is a tendency for water resistance and mechanical properties to deteriorate, and when it is greater than 1.7, optical properties and heat resistance tend to deteriorate.

The copolymer constituting the composition of the present invention is used to impart weather resistance, mechanical properties, optical properties, and moldability inherent to methacrylic resin.

Methyl methacrylate, which is the main component in the copolymer (IJ), is essential for imparting the weather resistance, optical properties, and mechanical properties inherent to methacrylic resin, and if the amount used is less than 80% by weight, When this happens, the value of the property decreases. Monomers that can be used for copolymerization with butyl methacrylate include acrylic esters such as methyl acrylate and ether acrylate;
Methacrylic acid esters such as ethyl methacrylate and butyl methacrylate, styrene, acrylonitrile, etc. are used, and these monomers are copolymerized in an amount of two or more types of il'i and 20% by weight or less.

The amount of copolymer (I) constituting the resin composition of the present invention is 1 to 99% by weight, preferably 5 to 95% by weight of the composition.
If it is less than 1% by weight, heat resistance will be poor, and if it exceeds 99% by weight, mechanical properties and weather resistance will be poor.

The amount of copolymer (6) used is 1 to 99% by weight, preferably 5 to 95% by weight. If it is less than 1% by weight, the mechanical properties and weather resistance will be poor, and if it exceeds 99% by weight, no improvement in heat resistance can be expected.

The composition of the present invention has a flow rate (FR) of 05 to 75.
(According to ASTM D-1238, 250℃, 10
It is particularly useful as a molding material that has an extrusion rate (f) for 10 minutes under a load of Ky/cm''.

The method for producing the uninvented composition is not particularly limited, and for example, the copolymer (1) may be produced by bulk polymerization, cloud polymerization, etc. in accordance with a conventional method, and the resulting copolymer (I') may be co-produced. A method of producing a blended resin by mixing with the polymer (6) and then melting, cross-fertilizing, and extruding at a temperature of 200 to 300°C;
Copolymer (I) is added to the monomer mixture for producing copolymer (6).
), and then suspension polymerization or bulk polymerization in an aqueous medium containing a dispersant; A method such as polymerization is adopted.

Further, in the composition of the present invention, additives such as ultraviolet absorbers, release agents, antioxidants, mold release agents, dyes and pigments may be added as necessary.

Hereinafter, the content of the present invention will be explained in more detail with reference to Examples.

Examples 1-3, Comparative Examples 1-2 Methacrylic 650 f, α-methylstyrene 507, styrene 1507, maleic anhydride 150
To the monomer mixture 10001, t-dodecylmercaptan 232 was added as a molecular weight regulator, and the mixture was placed in a 2-t separable flask equipped with a condenser, a thermometer, and a stirrer. Next, without stirring, blow in distillate gas to drive out the air in the system, and then heat to add 0.2% of the polymerization initiator Abhis isobutyronitrile at an internal temperature of 70°C.
2 was added, the internal temperature was maintained at 95° C. for 15 minutes, and then cooled in a room temperature trench to obtain a wrap-like partial polymer with a 600 centipoise temperature.

For this partial polymer iooor, 41 lauroyl peroxide and 5,0? , product name 11J P- as a release agent.
504'' (manufactured by Johoku Kagaku ■) o, 22, as an ultraviolet absorber product name 11 Tinuvinp II (Ciba Geigy ■g)
)o, 3r, trade name l1MarK329 as a stabilizer
” (manufactured by Adeka Arcus@) 11i+.

One portion of stearic acid monoglyceride was added as a mold release agent, and the mixture was sufficiently stirred to dissolve. This partial polymer mixture is
The mixture was poured into a mold consisting of a thermocouple set in a cell formed by two tempered glass plates spaced apart by a polyvinyl chloride gasket, and polymerized and cured in hot water at 80°C. After 30 minutes of confirming the time it took for the internal temperature to reach its peak after immersing it in hot water, the mold was removed from the hot water by 9 ounces of salt and treated in an air heating oven at 160°C for 2 hours. After cooling, the glass plate was removed to obtain a resin plate with a thickness of about 6 columns.

This plate was cut and crushed into pellets of about 3 to 4 tm++. This pellet was blended with II Acryvet V H11 manufactured by Mitsubishi Rayon @ in the proportions shown in Table 1 using a Hennel mixer, and then shaped into pellets using a twin-screw extruder at a temperature of 265°C. This pellet was injection molded under the following conditions, and the evaluation results in Table 20 were obtained from the obtained test piece (110 tone x 110 mm x 2 body thickness).

Injection molding machine: Nippon Steel New Co., Ltd., v-i7-65 type screw complete automatic injection molding machine Injection molding conditions Niji cylinder temperature 250-260℃, injection pressure 70D KSI/port 2 Mold temperature 60℃ Table 1 * MlviA : Methyl methacrylate α-MeSt
: α-Methylstyrene St: Styrene MAH: Maleic anhydride Table 2 *I ASTM D-648 *2 ASTM D-1003 *3 ASTM D-638 *4 Visual observation *5 Suga ■ weather resistance tester, temperature 60℃, Carbon arc lamp, 912 minutes of rainfall per hour Comparative Examples 3 to 5 To 1'000 r of a monomer mixture in which methyl methacrylate, α-methylstyrene, styrene, and maleic anhydride were mixed in the proportions shown in Table 3, Molecule i T-dodecyl mercaptan 261 was added as a regulator, and the mixture was placed in a 2-t separable flask equipped with a condenser, thermometer, and stirring bar.

Next, while stirring, the atmosphere was replaced with nitrogen, and then the polymerization initiator azobisisobutyronitrile was added at an internal temperature of 70° C. by heating.
259 was added thereto, and the internal temperature was kept at 95° C. for 15 minutes and then cooled to room temperature to obtain a silubular partial polymer.

For 1.000 F of this partial polymer, lauroyl peroxide 41, t-dodecyl mercaptan 502 as a molecular weight regulator, and trade name "JP-s" as a release agent.
D4" (manufactured by Johoku Kagaku@) 022, as a stabilizer, trade name "MarK 3291' (manufactured by Adeka Argus ■) 11, as an ultraviolet absorber, trade name 11 Tinuvin-P1
1 (manufactured by Ciba Geigy) 0.2? Then, stearic acid monoglyceride 11 was added as a mold release agent and dissolved with sufficient stirring. This partial polymer mixture was injected into a mold consisting of a thermocouple set in a cell made of two tempered glass plates spaced 5 mm apart through a polyvinyl chloride agricultural gasket, and heated with 80°C hot water. It was polymerized and cured inside. Then, check the time from immersion in hot water until the internal temperature reaches its peak, and after 60 minutes, remove the mold from hot water, and then
It was treated in an air heating oven at 60°C for 2 hours. After cooling Gala 2
The plate was removed to obtain a resin plate with a thickness of about 3 fins. This polymer was cut and crushed into pellets of approximately 6 to 4 prints.

The Bolifu shown in the table was shaped at 265° C. using a single screw extruder with a diameter of 40 mm. Using this pellet, injection molding was carried out under the same conditions as in Example 1, and the obtained test piece was measured. The results are shown in Table 4.

Examples 4 to 6, Comparative Example 6 Methyl methacrylate 6652, α-methylstyrene 55
A resin plate having a thickness of 6 mm was obtained in exactly the same manner as in the example except that a monomer mixture consisting of t, p-methylstyrene 1401 and maleic anhydride 140f was used. Cut this,
After pulverization, the blend was shaped into pellets using a twin-screw extruder (temperature: 265°C).

Table 5 *1 Methyl methacrylate-butyl acrylate copolymer (weight composition - 50:50) This pellet was injection molded in the same manner as in Example 1, and the obtained test piece was evaluated. The results are shown in Table 6.

Table 6

Claims (1)

[Claims] 1, (4) Methyl methacrylate monomer or partial polymer 4 o to 97% by weight (B) α-methylstyrene 1 to 20 weight% (C') Styrene or vinyl ester 121 to 20% weight%
and (D) a copolymer obtained by polymerizing a mixture of 1 to 20% by weight of maleic anhydride (1) A copolymer containing 1 to 99% by weight of maleic anhydride and 800% by weight or more of methyl methacrylate. (2) A heat-resistant methacrylic resin composition comprising 1 to 99% by weight. 2. When co-m coalescence (I) is the number of moles of α-methylstyrene is α, the number of moles of styrene or vinyltoluene is β, and the number of moles of maleic anhydride is r, the blending ratio of each component (α + β / r) The heat-resistant methacrylic resin composition according to claim 1, characterized in that the composition has a quantitative relationship of 0.9 to 1.7.