JPH0562146B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a polyester resin composition. More specifically, the present invention relates to a polyester resin composition that has improved flame retardancy and melt thermal stability of polyester, and has excellent mechanical properties and moldability. [Prior Art] Polyester is used in large quantities for mechanical parts, electrical parts, automobile parts, building material parts, etc., taking advantage of its characteristics as a material with an excellent balance of moldability and mechanical properties. On the other hand, flame retardancy is strongly required for these industrial materials in addition to the general balance of chemical and physical properties, and now the quality of polyester resin products is determined by the degree of flame retardancy imparted. It has even been said that Generally speaking, the method of adding brominated polystyrene to combustible plastics is to make them flame retardant.
57-39264) and methods of adding organic halides (Japanese Patent Publication No. 48-12413), but increasing the amount added for the purpose of imparting flame retardance only reduces mechanical strength and melt thermal stability. This also increases the decomposition of the flame retardant itself. Organic halogen compound flame retardants generally have poor melt thermal stability, so when blending them into resins, it is common to use several types of heat stabilizers and heat resisters together.
In addition, countermeasures such as molding at the lowest molding temperature have been taken, but sufficient effects have not been obtained. In the case of brominated polystyrene, the flame retardant itself has a good color and also has good moldability and fluidity when blended with a resin, so it is used in a fairly large amount. However, since it has poor thermal stability, if the residence time in the cylinder during molding is long, gas and burns are often generated due to decomposition, and at the same time, the flame retardance is also greatly reduced. For this reason, when the amount added is increased for the purpose of maintaining flame retardancy, product quality often deteriorates due to a vicious cycle such as further acceleration of decomposition. [Purpose of the Invention] As a method to solve these problems, we have developed a method that uses a specific brominated crosslinked aromatic copolymer and an antimony compound in combination to impart flame retardancy with a smaller amount than conventional additives. The present invention was accomplished by discovering a polyester resin composition which also has excellent melting thermal stability. [Structure of the Invention] The gist of the present invention is that thermoplastic polyester resin
100 parts by weight contains 0.5 to 100 parts by weight of a porous crosslinked aromatic copolymer with a bromine content of 40 to 80% by weight obtained by brominating a crosslinked aromatic copolymer and 1 to 40 parts by weight of an antimony compound. It consists in a polyester resin composition made of The brominated porous crosslinked aromatic copolymer used in the present invention is synthesized by the method (2-1) below and has a toluene swelling degree of 4 ml/g to 12 ml/g.
using a porous crosslinked aromatic copolymer, and 2-(2)
40 to 80% by weight of bromine atoms are bonded by this method. (2-1) Porous crosslinked aromatic copolymers are synthesized by adding a porosity agent that does not participate in polymerization to monovinyl monomers and polyvinyl monomers. Here, monovinyl monomers include monovinyl aromatic monomers such as styrene, vinyltoluene, and vinylnaphthalene, and examples of polyvinyl monomers include polyvinyl aromatic monomers such as divinylbenzene, divinylxylene, and trivinylbenzene. The body is useful. In addition, as a method for synthesizing porous copolymers, for example, the book "Chelate Resin/Ion Exchange Resin"
(edited by Shumasa Hojo, published by Kedansha in 1978) p. 136~
The method of adding a porosity-forming agent such as a precipitant or a linear polymer described on page 141 is useful. Polymerization can be carried out using a mixture of these materials by a known polymerization method. As a simple method, a method of heating in bulk or suspension in the presence of a polymerization initiator is advantageous. When polymerization is carried out in suspension, the amount of polymerization initiator is generally in the range from 0.05 to 5.0% by weight, based on the monomer mixture. Various polymerization initiators can be used as the polymerization initiator, but
Generally, peroxides such as benzoyl peroxide and lauroyl peroxide, and azo polymerization initiators such as azobisisobutyronitrile are useful. When polymerization is carried out in suspension, the monomer mixture is stirred in the presence of a suitable dispersant and water as a medium. Polymerization varies depending on the type of polymerization initiator, but in the case of benzoyl peroxide,
It is carried out under stirring at 80° C. for 8 to 20 hours. After polymerization, the obtained copolymer is thoroughly washed with water, additives are removed by operations such as extraction, and then dried. Here, the ratio of polyvinyl monomer to the total vinyl monomer, which is the sum of monovinyl monomer and polyvinyl monomer, of the crosslinked aromatic copolymer according to the present invention and the ratio of addition of the porosity agent are as described below. In order to facilitate the introduction of a certain amount of bromine in the process and to prevent coloration of the obtained bromide, the degree of toluene swelling of the porous aromatic copolymer is 4 ml/g to 12 ml/g, preferably 4.5 ml/g. g
The ratio of polyvinyl monomer to all vinyl monomers that satisfies this range of toluene swelling is 2 to 50% by weight, preferably 3 to 20% by weight. The ratio of the porosity-forming agent added to the total vinyl monomer is 10 to 200% by weight, preferably 20 to 150% by weight. The degree of toluene swelling, which indicates the degree of porosity of a crosslinked aromatic copolymer as used in the present invention, is based on the volume (Bml) when a dry crosslinked aromatic copolymer (Ag) is immersed in toluene and swelled. This value is calculated using the following formula. Toluene swelling degree (ml/g) = B (ml)/A (g) If this value is smaller than 4 ml/g, sufficient porosity cannot be imparted to the crosslinked aromatic copolymer, and the bromination reaction described below On the other hand, if this value is greater than 12 ml/g, it is difficult to synthesize crosslinked aromatic copolymers and bromination described below can be carried out stably. It is difficult and productivity is extremely low. (2-2) The porous copolymer obtained by the above method is brominated using a brominating agent, preferably from 0 to
Performed between 100℃. As the brominating agent, bromine generating agents such as sulfuryl bromide and molecular bromine can be used. When molecular bromine is used, suitable bromination temperatures are from 0 to 50°C, and such bromination reactions are usually completed in 2 to 20 hours. The amount of bromine atoms introduced varies depending on the amount of brominating agent used and the bromination reaction conditions, but preferably the bromine content in the obtained brominated copolymer is 40 to 80% by weight, preferably 50 to 80% by weight. It is preferable to carry out the bromination so that the amount is 70% by weight. In order to make the bromination reaction proceed smoothly, it is preferable to use a catalyst such as ferric chloride or aluminum chloride. The amount of such catalyst preferably ranges from 0.025 to 0.1 g per gram of copolymer. Further, when carrying out the bromination reaction, it is preferable to swell the copolymer in advance with a swelling agent such as dichloroethane or dibromoethane. After the bromination reaction, the brominated crosslinked copolymer produced as described above is washed with a sufficient amount of water and an organic solvent such as methanol or acetone, and then dried. Incidentally, if the bromine content is less than the above range, flame retardancy cannot be imparted, and therefore the amount added becomes large and no effect can be expected. If the amount exceeds the above range, the bromination reaction will be difficult to proceed and the brominated product will be colored. The thermoplastic polyester resin used in the present invention is polyalkylene terephthalate obtained by a polycondensation reaction of terephthalic acid or its dialkyl ester with aliphatic glycols, or a copolymer mainly composed of this. Examples include polyethylene terephthalate and polybutylene terephthalate. Examples of the aliphatic glycols mentioned above include ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, etc. Along with these aliphatic glycols, other diols or polyhydric alcohols such as aliphatic glycols can be used. 30% by weight or less of cyclohexanediol, cyclohexanedimethanol, xylene glycol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl)propane,
-Hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxyethoxyphenyl)propane, 2,2-bis(4-hydroxyethoxy-3,5-dibromophenyl)propane, glycerin, pentaerythritol, etc. may be used in combination. In addition, together with terephthalic acid or its dialkyl ester, other dibasic acids, polybasic acids, or their alkyl esters, such as phthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphthalic acid, diphthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphthalic acid, etc. Enyldicarboxylic acid, adivic acid, sebacic acid, trimesic acid, trimellitic acid, alkyl esters thereof, and the like may be used in combination. The blending ratio is 0.5 to 100 parts by weight, preferably 2 to 30 parts by weight, of the brominated crosslinked aromatic copolymer per 100 parts by weight of the polyester resin, but the bromine content relative to the total amount of resin components is 0.3 to 30 parts by weight. %,
The content is preferably 1.2 to 15 wt%. Further, when adding the above-mentioned flame retardant to polyester resin to make it flame retardant, an excellent flame retardant effect can be obtained by adding an antimony compound as a flame retardant aid. As the flame retardant aid, antimony compounds such as antimony trioxide, antimony pentoxide, and antimony tartrate are used, and antimony trioxide is particularly preferred. The amount used is 1 to 40 parts by weight, preferably 2 to 20 parts by weight, per 100 parts by weight of the polyester resin. If the amount is too low, the effect of promoting flame retardancy will be small. On the other hand, if the amount is too large, the mechanical properties will be impaired. In order to blend the flame retardant of the present invention into a synthetic resin, it may be mixed in any order by a known method, such as a method of mixing and extruding using an extruder, a method of simply mixing and direct injection molding, a method of simply mixing and direct injection molding, Examples include a method of adding it during production. Furthermore, fiber reinforcement materials such as glass fibers, carbon fibers, and metal whiskers, surface-treated fiber reinforcement materials with epoxy systems, epoxy silane systems, and amino silane systems to improve adhesion with resins, and combustion drippings such as asbestos. inhibitors, silica, alumina, silica alumina, silica magnesia, titania, calcium carbonate, talc, gypsum and glass flakes, fillers such as glass beads, dyes and pigments and paraffins, fatty acid esters,
Fatty acid metal salts, lubricants such as bisamides, esters of pentaerythritol such as pentaerythritol tetrakis (dodecylthiopropionate), carbodiimide compounds such as bis(diisopropylphenyl)carbodiimide, bisphenol A dicrycidyl ether , allyl glycidyl ether, 3,4 epoxycyclohexyl, 3′,4′ epoxycyclohexane carboxylate, and other epoxy compounds;
Other known additives may also be used in combination. To give an example of the usage range of these additives (based on 100 parts by weight of thermoplastic polyester resin), in the case of pentaerythritol ester, carbodiimide, and epoxy compound, the amount range is 0.01 to 5.
It is 5 to 100 parts by weight in the case of a fibrous reinforcing material. The amount of asbestos used is preferably 0.1 to 10 parts by weight per 100 parts by weight of polyester resin.
The amount is 0.5 to 5 parts by weight, and if this amount is too small, no effect of preventing dripping can be expected, and on the other hand, if it is too large, no particular improvement in the effect can be expected. The composition of the present invention has excellent flame retardancy, mechanical properties and thermal stability, and is of great value as an engineering plastic. The composition of the present invention can be made into molded products of various shapes such as three-dimensional molded products, various containers, films, sheets, and tubes by various molding methods such as injection, extrusion, blowing, and compression. It is suitable as a material for electronic parts, automobile parts, and other industrial uses. [Examples] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. In the examples, "parts" and "%" indicate "parts by weight" and "% by weight," respectively. Further, the tensile strength was measured according to ASTM D 638, and the bending strength was measured according to ASTM D 790. Thermal stability and moldability were determined by injection molding the test piece for strength measurement, varying the residence time in the cylinder, observing the shape of the molded product with the naked eye, and then conducting a strength test. In addition, changes in color tone can be measured using a color difference meter (Tokyo Denshoku Co., Ltd. TC-
55D), calculate the XYZ tristimulus values,
The YI value was calculated using the following formula. YI value = (1.28X-1.06Z) x 100/Y Flammability test is conducted by Undev Writcis Labovy
Subyeit No.94 test (Flame retardant test of plastic materials
The flame retardance was evaluated by molding a molded article in accordance with UL94 (February 1, 1974) (labeled as UL94 VB test). Example 1 Polybutylene terephthalate (NOVADUR 5008 manufactured by Mitsubishi Kasei, NOVADUR is a registered trademark) with an intrinsic viscosity of 0.85 was cross-linked with 10% by weight of divinylbenzene to a toluene swelling degree of 5.0 with the composition shown in Table 1.
After adding 500 g of dichloroethane to 100 g of porous polyethylene of ml/g and leaving it for 1 hour, 5.0 g of iron chloride was added.
After adding g and 434 g of molecular bromine and reacting at room temperature for 8 hours, water was added and heated at 90°C to azeotropically distill dichloroethane. Then, the copolymer was washed with water, and then acetone Brominated cross-linked polystyrene with a Br content of 63.5% obtained by washing with hydrochloric acid and water and drying, antimony trioxide (manufactured by Mikuni Seirei Co., Ltd.), and glass fiber (manufactured by Asahi Fiber Glass Co., Ltd.)
CSO3MA486A), asbestos (Tomoe Kogyo Co., Ltd. R-
A mixture of 244) was prepared and melt-kneaded at 250°C using a 40 mmφ vented extruder manufactured by Isuzu Kako Co., Ltd., and extruded into pellets. The pellets are processed using a 3.9 oz injection molding machine (N-100B type manufactured by Japan Steel Works).
Using a mold for molding test pieces specified by ASTM and a mold for UL combustion pieces specified by UL-94, the resin temperature was 260℃, the mold temperature was 80℃, the injection time was 10 seconds, and the cooling time was 20 seconds (UL The combustion pieces were injection molded in 10 seconds). The physical properties of the obtained molded article were measured using the method described above. The results were as shown in Table 1 below. As a comparative example, non-crosslinked brominated polystyrene (Pyrocheck manufactured by Nissan Ferro Organic Co., Ltd.) was used as a comparative example.
68PB, bromine content 65-67 wt%) is also shown. Example 2 DMT1.0mol, 1.4-BG1.2mol and 2.2bis(4
-Hydroxyethoxy-3,5-diglomphenyl) propane 0.06 mol was used as the base resin, and the same compounding agents as in Example 1 were used, except that a polyester resin with an intrinsic viscosity of 0.85 and a halogen content of 6% was used. It was kneaded into pellets. Table 2 shows the blending ratio and molding results. In Comparative Example, the same compounding agents as in Comparative Example 1 were used, except that a halogen-containing polyester resin was used as the base resin, and the mixture was kneaded into pellets. The blending ratio and molding results are also listed. Example 3 The following (Table 3) was added to polybutylene terephthalate (NOVADUR5010 manufactured by Mitsubishi Kasei) with an intrinsic viscosity of 1.10.
A mixture of the brominated crosslinked polystyrene used in Example 1 and Bb ₂ O ₃ having the composition was kneaded in the same manner as in Example 1, pelletized and injection molded, and the physical properties were measured. The results are shown in Table-3. As a comparative example, non-crosslinked brominated polystyrene (Pyrocheck) was used as in Example 1.
68PB) are also shown. Example 4 Polybutylene terephthalate (NOVADUR5008 manufactured by Mitsubishi Kasei) with an intrinsic viscosity of 0.85 was mixed with 100 g of porous polyethylene with a toluene swelling degree of 8.2 ml/g cross-linked with 4 weight percent divinylbenzene and 1000 g of dichloroethane with the composition shown in Table 4. was added and allowed to stand for 1 hour, then 5.0 g of iron chloride and 434 g of molecular bromine were added and the reaction was carried out at room temperature for 8 hours. Water was then added and heated at 90°C to azeotropically distill dichloroethane. Then, the copolymer was washed with water, further washed with acetone and hydrochloric acid, and then washed with water and dried.
A mixture of brominated crosslinked polystyrene with a Br content of 63.8%, antimony trioxide, glass fiber, and asbestos was prepared and kneaded in the same manner as in Example 1, and the physical properties of injection molding were measured. The results are shown in Table 4. It was hot on the street. As a comparative example, the results obtained when non-crosslinked brominated polyethylene (same as Comparative Example 1) were used are also shown.

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〔Effect of the invention〕

The composition according to the invention has excellent flame retardancy, mechanical properties and thermal stability.

Claims (1)

[Claims] 1 The bromine content obtained by brominating a crosslinked aromatic copolymer is added to 100 parts by weight of a thermoplastic polyester resin.
40~80% by weight porous crosslinked aromatic copolymer 0.5~
A polyester resin composition containing 100 parts by weight and 1 to 40 parts by weight of an antimony compound.