JPH04503083A - Aromatic triester plasticized copolymer of acrylonitrile and styrene - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Aromatic triester plasticized copolymer of acrylonitrile and styrene The present invention comprises: A new material with high transparency, good color retention and excellent adaptability to injection molding technology. The present invention relates to resinous compositions. In particular, the invention provides that all of the desirable properties of the copolymer are suitable to yield a composition with good melt flow properties without compromising the properties of the This invention relates to plasticized copolymers of styrene and acrylonitrile.

Copolymers of styrene and acrylonitrile and their preparation are well known to those skilled in the art. It is. The copolymer has good resistance to organic solvents and is very transparent . However, in some applications, it results in faster cycle times and other molding improvements. Therefore, it is desirable to provide improved or increased melt flow properties. this is , achieved by the use of plasticizers. For example, styrene/acrylonitrile copolymerization The use of epoxidized soybean oil as a suitable plasticizer for body applications is well known to those skilled in the art. Ru. However, disadvantageously, resins containing epoxidized soybean oil are particularly susceptible to high temperatures for long periods of time. Has a tendency to discolor when exposed to heat.

Furthermore, the formation of objects with complex and intricate shapes using styrene/acrylonitrile resin Mold makers use very high molding temperatures to provide improved resin melt flow. must be used often. Already known plasticizers such as alkyl phthalates in such harsh environments due to "sweating", or the deposition of plasticizer on the mold surface. doesn't work.

The main object of the present invention is to improve the melt flow rate of copolymers of acrylonitrile and styrene. and other properties. Another object of the invention is to Acrylonitrile and salt without compromising the desired clarity or color properties of the combination. The object of the present invention is to provide a means for plasticizing a tyrene copolymer. Another object of the invention is , "sweat out" i.e. loss of plasticizer and molding. without encountering the problem of its condensation on the cold surfaces of the equipment and injection molded parts. The object is to produce new and more useful compositions that can be used at extreme temperatures.

Aromatic compounds in which the ester group contains an alkyl or aryl group of up to 20 carbon atoms Triesters of recarboxylic acids, especially trimellitic acid, are excellent for styrene and acrylic acids. Compatible with copolymers of lonitrile and losing the properties of crystalline polymers This effectively improves the melt flowability of the molten polymer. In particular, these polymers Shows little color or plasticizer sweat-out.

The present invention preferably comprises 65-80% by weight styrene and 20-35% by weight acrylate. Used in copolymers of rylonitrile. Elastomeric impact modifiers e.g. Butaje based rubbers, conjugates of ethylene and propylene and optionally non-conjugated dienes. The polymer and the alkyl acrylate rubber can also be present in the copolymer. appropriate amount of opposition The impact modifier is 1-20% by weight, preferably 5-15%. The copolymer is an emulsion It can be produced by polymerization, bulk, solution or suspension polymerization.

Preferred plasticizers for the practice of this invention have the structural formula %) (In the formula, Ar is an aromatic group of up to 20 carbon atoms, and R is an alkyl group of up to 20 carbon atoms, or aryl group) It is an acid triester with A preferred triester is a direct triester of trimellitic acid. Chain C44 alkyl triester. Particularly preferred esters are trimellitic tridecyl acid, tridodecyl trimellitate, tri-n-octyl trimellitate and mixed c4-1° linear alkyl trimellitates. Straight chain or linear Al Quilt triesters are particularly preferred for improved color stability. long heating time The discoloration of additives due to the large defect of tertiary hydrogen protons compared to secondary hydrogen moieties This seems to be due to stability.

The plasticized copolymer can be processed using any of the conventional mixing machines such as roll mills, vans, etc. In a Barry type mixer, extruder, etc. (which can be heated to soften the copolymer), Manufactured by mixing the desired plasticizer and copolymer. Plasticizers also polymerize coated on the surface of body particles and later melted and incorporated into a polymer or incorporated into the polymer mixture and thus incorporated into the polymerization couple prior to devolatilization and granulation. will be combined.

The amount of plasticizer used will depend on the final use of the composition. Aromatic acid tri A plasticizing amount of ester is used, ie an amount sufficient to improve the properties of the polymer. Possible The preferred amount of plasticizer is 0.1-5% by weight, more preferably 0.5-2.5% by weight. be. The optimal proportion of triester is determined by making test samples and increasing the melt flow rate. by measuring the adhesion, rheology and other desired physical properties (of the resulting resin). It can be easily attached.

The new composition provides injection molded articles with improved moldability and high clarity. is of excellent value in manufacturing. Epoxidized soybean oil and exposed to high temperatures When the resulting copolymer results in less discoloration. Phthalate or terephthalate When compared to diester plasticizers, mold sweating is substantially improved and bending A small improvement in strength is observed. These results are expected or expected based on known teachings. is not expected.

Other additives such as colorants, UV stabilizers, reinforcement aids, blowing agents, fibers, fillers and the like are included in the copolymer composition of the present invention. Details of manufacturing and evaluation of new products. Details are presented with respect to specific examples below.

Example 1 Using a recirculating coil reactor, about 5% by weight acrylonitrile and about 15,000 A catalytic styrene acrylonitrile was prepared having a molecular weight (Mw) of 0. (Tess The actual molecular weights of the analyzed samples are shown in Table ■. ) Using a 0.2 inch (20 mm) Welding Engineers extruder Then, a plasticizer was blended into the styrene/acrylonitrile raw material. various plasticity agent was added to give a final plasticizer content of 1.0% by weight. Results of physical property tests The fruits are included in Table ■.

Table 1 Plasticizer (%) Polymer MFR’ Vieat” Bending strength 3M Ri A river use [Island R Kumie W Ni -"140 9.8 229 18400ESBO" 1.0 138 11 ．． 2 225 17800 DIDP" 1.0 144 11.1 227 1 740ONODP” 1.0 139 11.5 225 17000TOTM ’1.0 145 11.4 225 1760ONONDTM” 1.0 140 11.5 226 176001 Melt flow rate g/10 min/ASTM D1238 Condition IZ Vicat heat softening temperature °C 3 Bending strength ASTM D790 4 Epoxidized soybean oil 5 Di-isodecyl phthalate 6 n-octyl phthalate, n-decyl 7 tri(2-ethyl trimellitate) hexyl) 8 Reaction with a mixture of trimellitic acid and linear C11-111 alcohol Comparison of n-octyl and n-decyl trimellitate formed by reaction* As can be seen by examining Table I, the trimellitate ester is gave slightly improved melt flow rates compared to using In addition, trimellitate The decrease in bending strength related to Stell is greater with phthalate diester plasticizers. There wasn't. Compared to phthalate diesters, Trimerite The esters were shown to have improved properties.

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Claims (5)

[Claims] 1. plasticizer formula Ar(C(O)OR)3 (In the formula, Ar is an aromatic group of up to 20 carbon atoms, and R is an alkyl group of up to 20 carbon atoms or is an aryl group) is an aromatic triester corresponding to 6 Copolymer of 5-80% by weight styrene and 35-20% by weight acrylonitrile and a plasticizing amount of a plasticizer. 2. The composition of claim 1, wherein the aromatic triester is a trimellitic acid triester. . 3. The composition of claim 1 comprising 0.1-5% by weight of aromatic triester. 4. The composition of claim 1, wherein R is linear C6-20 alkyl. 5. Trimellitic acid ester is tri-n-octyl trimellitate, trimellitate Claim 2: Tridecyl torate or mixed C8-10 linear alkyl trimellitic acid. Composition of.