JP4841178B2 - Resin composition and molded body - Google Patents

Description

  The present invention relates to a flame retardant resin composition and a molded body, and particularly relates to a flame retardant and heat resistant resin composition and a molded body.

  Plastics are now widely used in every field such as daily life and industry, and the demand for plastics is increasing year by year. Plastics are used in various applications utilizing their excellent physical properties, molding processability, etc., for example, in the molding field of film packaging materials, home appliances, OA equipment, automobile parts and the like.

  Flame retardant properties are required for molded articles used for home appliances, OA equipment, automobile parts and the like to prevent fire. For example, since polystyrene and ABS resin are easily combusted, halogen-based flame retardants such as brominated flame retardants have been mainly used. Further, there is a flame retardancy imparting method in which an organic halogen compound and antimony trioxide are blended and the chemical and physical synergistic effects of both are used. However, resin compositions containing organic halogen compounds may generate harmful gases such as dioxins from halogen flame retardants during combustion or molding, or when molded products are incinerated. There were safety issues in incineration and thermal recycling.

  Therefore, in recent years, development of non-halogen flame retardants has been actively performed. For example, a method of blending a phosphorus-based flame retardant represented by a phosphate ester compound is generally used, but the phosphate ester-based compound also acts as a plasticizer and therefore imparts flame retardancy. On the other hand, heat resistance is greatly reduced.

For this reason, nitrogen compounds are attracting attention as substitute materials for non-halogen compounds and non-phosphorus compounds.
Examples of the nitrogen compound include melamine, melamine cyanurate, melam, melon, melamine (mono / pyro / poly) phosphate and the like. For example, melamine has a low decomposition temperature of about 200 ° C., and as disclosed in Patent Documents 1 to 4, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polybutylene terephthalate (hereinafter “PBT”). Melamine is decomposed at a molding temperature of an aromatic polyester such as (which may be abbreviated to be abbreviated as “)”, resulting in molding failure. Melamine cyanurate has a high decomposition temperature of about 320 ° C., so it can be used for PET, PBT, etc., but it has a low effect of imparting flame retardancy, so it needs to be blended in large quantities. Since the physical properties are remarkably lowered, it is very difficult to use for home appliances, automobile parts and the like.

  Moreover, the method of using a nitrogen compound and a phosphorus compound together is disclosed in Patent Documents 5 to 7, and flame retardancy can be imparted using these techniques, but the safety of a phosphorus flame retardant, The problem of environmental harmony will remain.

JP 54-112958 A Japanese Patent Publication No. 60-33850 Japanese Patent Publication No.59-50184 Japanese Examined Patent Publication No. 62-39174 Japanese Patent Laid-Open No. 3-281652 Japanese Patent Laid-Open No. 5-70671 JP-A-5-287119

  As described above, in the conventional method for imparting flame retardancy, it has been very difficult to make the thermoplastic resin flame-retardant with a nitrogen-based compound, particularly melamine.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a resin composition and a molded body having heat resistance and flame retardancy.

  The resin composition of the present invention is a resin composition containing as a main component a mixture formed by blending melamine with polybutylene succinate, and the blending amount of the melamine is 15% by mass or more and 80% by mass in the mixture. It is characterized by the following.

  Further, the resin composition of the present invention can further contain a carbodiimide compound, and the amount of the carbodiimide compound is 0.5 parts by mass or more with respect to 100 parts by mass of the polybutylene succinate and melamine mixture. It is preferable that it is 10 mass parts or less.

  The molded product of the present invention is characterized by using any of the above resin compositions.

  According to the present invention, by blending melamine with polybutylene succinate having a low molding temperature and heat of combustion, excellent flame retardancy can be imparted without impairing the heat resistance inherent in polybutylene succinate, For example, it is possible to provide a resin composition and a molded body that satisfy the V-0 standard or the VTM-0 standard in the UL94 vertical combustion test.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described below.
The resin composition of this invention contains the mixture which consists of polybutylene succinate and a melamine as a main component.

  The polybutylene succinate used in the present invention is obtained by polymerizing succinic acid and 1,4-butanediol. As polybutylene succinate, for example, “GSPla” series manufactured by Mitsubishi Chemical Corporation, “Bionore” series manufactured by Showa High Polymer Co., Ltd., and the like are commercially available. In the present invention, the polybutylene succinate preferably has a weight average molecular weight of 50,000 or more and 400,000 or less, more preferably 100,000 or more and 240,000 or less. If the polybutylene succinate has a weight average molecular weight of 50,000 or more, practical physical properties can be expressed, and if it is 400,000 or less, the melt viscosity is too high to cause inferior moldability.

  Melamine used in the present invention has a chemical name of 2,4,6-triamino-1,3,5-triazine and is a white crystalline powder. For example, representative examples of commercially available products include “Yucamamine” manufactured by Mitsubishi Chemical Corporation.

  As the blending amount of melamine, the proportion of melamine in the mixture of polybutylene succinate and melamine is preferably 15% by mass or more and 80% by mass or less, and preferably 20% by mass or more and 50% by mass or less. More preferably, it is 25 mass% or more and 40 mass% or less. When the blending amount of melamine is less than 15% by mass in the mixture, the effect of imparting flame retardancy is not sufficient, and when it exceeds 80% by mass, impact resistance and moldability may be deteriorated.

In the present invention, a carbodiimide compound can be further blended in order to impart hydrolysis resistance. Preferred examples of the carbodiimide compound to be used include those having a basic structure represented by the following general formula.

-(N = C = N-R-) n-

However, in the formula, R represents an organic bond unit, and may be, for example, aliphatic, alicyclic or aromatic. n represents an integer of 1 or more, and is usually appropriately determined between 1 and 50. When n is 2 or more, two or more R may be the same or different.

  Specifically, for example, bis (dipropylphenyl) carbodiimide, poly (4,4′-diphenylmethanecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (tolylcarbodiimide), poly ( Examples of the carbodiimide compound include diisopropylphenylenecarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly (triisopropylphenylenecarbodiimide), and the like. These carbodiimide compounds may be used alone or in combination of two or more.

  Specific examples of the carbodiimide compound include “STABAXOL” series manufactured by Rhein Chemie, “Carbodilite” series manufactured by Nisshinbo Co., Ltd., and the like.

  The compounding amount of the carbodiimide compound is preferably 0.5 parts by mass or more and 10 parts by mass or less, preferably 1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the mixture of polybutylene succinate and melamine. More preferably. If the blending ratio of the carbodiimide compound is 0.5% by mass or more, the effect of imparting durability can be exhibited, and if it is 5 parts by mass or less, the resin composition is softened and heat resistance is impaired. There is nothing.

  In the resin composition of the present invention, additives such as a heat stabilizer, an antioxidant, a UV absorber, a plasticizer, a nucleating agent, a light stabilizer, a pigment, and a dye are added within a range not impairing the effects of the present invention. Can be blended.

Next, a method for forming a molded body using the resin composition of the present invention will be described.
Polybutylene succinate, melamine, and if necessary, raw materials such as carbodiimide compounds and other additives are put into the same extruder or injection molding machine, kneaded directly, and molded to form Can be formed. Alternatively, a dry blended raw material is extruded into a strand shape using a twin-screw extruder to produce pellets, and the pellets are placed in an injection molding machine, an extruder, etc. to form a film, sheet, plate, etc. The molded body can be formed.

  Regardless of which method is employed, it is necessary to consider a decrease in molecular weight due to decomposition of the raw material, but the latter is preferably selected in order to uniformly mix the raw materials. For example, polybutylene succinate, melamine, and, if necessary, carbodiimide compound, other additives, etc. are sufficiently dried to remove moisture, then melt mixed using a twin screw extruder, and strand Extrude into shape to produce pellets. It is preferable to select the melt extrusion temperature as appropriate in consideration of the viscosity of the mixed resin changing depending on the mixing ratio with polybutylene succinate, melamine, and other additives. In practice, a temperature range of 160 ° C. to 230 ° C. is usually selected.

  After the pellets produced by the above method are sufficiently dried to remove moisture, a molded body such as a film, a sheet, or an injection molded body is formed. A roll stretching method, a tenter stretching method, a tubular method, an inflation method, or the like is employed as a molding method for a film, a sheet, and the like. Is adopted.

  As a method for producing an injection-molded body, for example, an injection molding method such as an injection molding method, a gas assist molding method, or an injection compression molding method generally employed when molding a thermoplastic resin can be employed. In addition to the above methods, an in-mold molding method, a gas press molding method, a two-color molding method, a sandwich molding method, PUSH-PULL, SCORIM, or the like can also be employed in accordance with other purposes. However, the injection molding method is not limited to these.

  The injection molding apparatus used is a general injection molding machine, gas assist molding machine, injection compression molding machine, etc., molding molds and incidental equipment used in these molding machines, mold temperature control device, raw material drying device Etc. The molding conditions are preferably such that the molten resin temperature is in the range of 160 ° C to 230 ° C in order to avoid thermal decomposition of the resin in the injection cylinder.

Polybutylene succinate has high crystallinity and is excellent in heat resistance and impact resistance. By blending melamine with polybutylene succinate to make it flame retardant, heat resistance of home appliances, OA equipment, automobile parts, etc. Can be used for applications that require heat resistance, flame retardancy, and impact resistance.

  The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples, and various applications are possible without departing from the technical scope of the present invention. In addition, each Example and each comparative example measured and evaluated by the method shown below.

(1) Flame resistance (UV94V, VTM)
Using a test piece of length 135.0 mm × width 13.0 mm × thickness 1.5 mm, a combustion test was performed at n = 5 based on the safety standard UL94 vertical combustion test procedure of Underwriters Laboratories. The UL94 vertical combustion test (VTM) was similarly performed on a thin sheet (length 135.0 mm × width 13.0 mm). Judgment was made based on the criteria of the UL94 vertical combustion test (UL94V, VTM), and those satisfying the V-0 standard or VTM-0 were regarded as acceptable.

(2) Decomposition rate The decomposition rate (decrease rate of weight average molecular weight) when melamine or melamine cyanurate was blended was calculated by the following formula. The practical use standard was a decomposition rate of 10% or less.

Decomposition rate (%) = [(ab) / a] × 100
a: Weight average molecular weight of resin composition when melamine or melamine cyanurate is not blended b: Weight average molecular weight of resin composition when melamine or melamine cyanurate is blended

(3) Durability Based on Japanese Industrial Standard JIS K-7110, No. 2 A test piece (notched, length 64.0 mm x width 12.7 mm x thickness 4.0 mm) manufactured by Toyo Seiki Seisakusho Co., Ltd. JISL-D was used to measure the Izod impact strength at 23 ° C.
Using a small environmental tester SH-241 manufactured by ESPEC CORP., The test piece was subjected to a wet heat test under the conditions of a temperature of 85 ° C. and a relative humidity of 80% RH. The Izod impact strength after 100 hours was measured, and the Izod impact strength before the wet heat test and the Izod impact strength after 100 hours were substituted into the following formula to calculate the Izod impact strength retention rate. When durability is required for the molded body, the Izod impact strength retention is preferably 70% or more. If the Izod impact strength retention is 70% or more, the strength does not deteriorate. .

Izod impact strength retention rate (%) =
(Izod impact strength after wet heat test / Izod impact strength before wet heat test) × 100

Example 1
GSPla AZ91T (weight average molecular weight 180,000) manufactured by Mitsubishi Chemical Corporation was used as the polybutylene succinate, and the trade name “Yucamamine” manufactured by Mitsubishi Chemical Corporation was used as the melamine. GSPla AZ91T and eucamamine were dry blended in a mass ratio of 85 parts by mass: 15 parts by mass, and then compounded at 180 ° C. using a 40 mmφ small co-directional twin screw extruder manufactured by Mitsubishi Heavy Industries, Ltd. The pellet shape. The obtained pellets were used as a test piece for flame retardancy evaluation using an injection molding machine “IS50E” (screw diameter: 25 mm) manufactured by Toshiba Machine Co., Ltd. A 5 mm plate (test piece) was obtained by injection molding. However, the main molding conditions are as shown below.

・ Temperature condition: Cylinder temperature (190 ℃) Mold temperature (30 ℃)
・ Injection conditions: Injection pressure (115 MPa) Holding pressure (55 MPa)
・ Weighing conditions: Screw rotation speed (65rpm) Back pressure (15MPa)

  About the obtained injection molded object (test piece), the flame retardance (UL94V) and the decomposition rate were evaluated. The results are shown in Table 1.

(Example 2)
Pellets were produced in the same manner as in Example 1 except that the blending ratio of polybutylene succinate and eucamamine was changed so that GSPla AZ91T: eucamamine = 70: 30 in mass ratio. Further, using the obtained pellets, injection molding was performed in the same manner as in Example 1 to prepare a test piece for flame retardancy evaluation. Furthermore, injection molding was performed using the obtained pellets in the same manner as in Example 1, and an injection molded article for durability test (length 64.0 mm × width 12.7 mm × thickness 4.0 mm test piece) ) Was produced.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1. Moreover, durability evaluation was performed about the injection molded object (test piece) for a durability test. The results are shown in Table 2.

(Example 3)
In Example 1, pellets were prepared in the same manner as in Example 1 except that the blending ratio of polybutylene succinate and eucamamine was changed so that the mass ratio was GSPla AZ91T: eucamamine = 50: 50. Then, an injection molded body (test piece) was prepared.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

Example 4
In Example 1, pellets were produced in the same manner as in Example 1 except that the blending ratio of polybutylene succinate and eucamamine was changed so that the mass ratio was GSPla AZ91T: eucamamine = 30: 70. Then, an injection molded body (test piece) was prepared.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Example 5)
In Example 1, the blending ratio of polybutylene succinate and eucamamine was dry blended so that the mass ratio was GSPla AZ91T: eucamamine = 80: 20, and then 40 mmφ single screw extrusion manufactured by Mitsubishi Heavy Industries, Ltd. It knead | mixed at 190 degreeC using the machine. Next, after extruding from the die, it was brought into contact with a casting roll at about 50 ° C. and quenched to prepare a sheet having a thickness of 200 μm. A sheet test piece having a length of 135.0 mm and a width of 13.0 mm was cut out from the obtained sheet, and the flame resistance (UL94VTM) and the decomposition rate of the sheet test piece were evaluated. The results are shown in Table 1.

(Comparative Example 1)
In Example 1, an injection molded article (test piece) was produced in the same manner as in Example 1 except that a pellet made of polybutylene succinate GSPla AZ91T was produced without using melamine.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Comparative Example 2)
In Example 1, instead of polybutylene succinate, polyethylene terephthalate (“Unipet RT523C” manufactured by Nihon Unipet Co., Ltd., IV = 0.7) was used, and Unipet RT523C and eucamamine were 70 by mass ratio. : Pellets were produced in the same manner as in Example 1 except that the mixture was mixed so as to be 30, and an injection molded article (test piece) was produced.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1. The obtained injection-molded product was a molded product whose appearance was remarkably impaired.

(Comparative Example 3)
In Example 1, instead of polybutylene succinate, polylactic acid (“Nature Works 4032D” manufactured by Cargill Dow, L-lactic acid / D-lactic acid = 98.6 / 1.4, weight average molecular weight 200,000) The pellets were produced in the same manner as in Example 1 except that Nature Works 4032D and Eucamamine were mixed at a mass ratio of 70:30, and an injection molded article (test piece) was produced. .
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Comparative Example 4)
In Example 1, instead of polybutylene succinate, polycaprolactone ("Cell Green P-H7" manufactured by Daicel Chemical Industries, Ltd., average molecular weight 120,000) was used, and by mass ratio, P-H7: eucamamine = 70 : Pellets were produced in the same manner as in Example 1 except that they were blended at a ratio of 30 and dry blended, and injection molded articles (test pieces) were produced.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Comparative Example 5)
In Example 1, melamine cyanurate (manufactured by Nissan Chemical Industries, Ltd., MC-860) was used instead of melamine, and the mass ratio was changed to GSPla AZ91T: MC-860 = 70: 30. Pellets were produced in the same manner as in Example 1, and an injection molded article (test piece) was produced.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

  As is apparent from Table 1, the injection molded articles comprising the resin compositions of Examples 1 to 4 and Example 5 of the present invention have flame retardancy based on the UL94 vertical combustion test of V-0 standard or VTM-0 standard. It was found that it was satisfying and excellent in flame retardancy. Moreover, since the heat resistance of the polybutylene succinate and the characteristic of impact resistance did not fall, the resin composition of Examples 1-5 had the outstanding heat resistance and impact resistance.

  On the other hand, as is clear from Table 1, it was found that the results of the flame retardant test for the injection-molded articles made of the resin compositions of Comparative Examples 1 to 5 were all worse than the V-2 standard. Moreover, in Comparative Examples 2-4 which mix | blended melamine with polyester-type resin, such as PET and polylactic acid, it turned out that a melamine decomposes | disassembles and molecular weight falls and the flame-retardant effect is not expressed. Moreover, in the comparative example 5 which mix | blended melamine cyanurate as a flame retardant instead of melamine, it turned out that the flame-resistant provision effect is low and shows V-2 reference | standard.

(Example 6)
In Example 2, “Carbodilite HMV-8CA” manufactured by Nisshinbo Co., Ltd. was used as a carbodiimide compound, and dry blended at a mass ratio of GSPla AZ91T: Yucamamine: Carbodilite HMV-8CA = 70: 30: 1. In the same manner as in Example 2, an injection-molded body for a durability test (length 64.0 mm × width 12.7 mm × thickness 4.0 mm test piece) was produced. The durability test similar to Example 2 was done about the obtained injection molded object. The results are shown in Table 2.

(Example 7)
In Example 2, “Carbodilite HMV-8CA” manufactured by Nisshinbo Co., Ltd. was used as a carbodiimide compound, and dry blended in a mass ratio of GSPla AZ91T: Yucamamine: Carbodilite HMV-8CA = 70: 30: 3. In the same manner as in Example 2, an injection-molded body for a durability test (length 64.0 mm × width 12.7 mm × thickness 4.0 mm test piece) was produced. The durability test similar to Example 2 was done about the obtained injection molded object. The results are shown in Table 2.

  As is clear from Table 2, it was found that durability can be remarkably improved by further blending a carbodiimide compound with polybutylene succinate and melamine.

  As described above, according to the present invention, since flame retardancy can be imparted without impairing the heat resistance of polybutylene succinate, a resin composition having flame retardancy and heat resistance can be obtained. Moreover, since the molded object formed using the resin composition of this invention is equipped with the outstanding flame retardance and heat resistance, it is widely used for the household appliances and motor vehicle use which a flame retardance, heat resistance, etc. are required. Can be used.

  The resin composition of the present invention can be widely used for applications that require both flame retardancy and heat resistance, and can be used, for example, for home appliances and automotive products. In addition, it can also be used as electrical and electronic equipment parts, daily necessities, food containers, and other general injection molded products.

Claims (3)

  A resin composition containing as a main component a mixture formed by blending melamine with polybutylene succinate, wherein the blending amount of the melamine is 15% by mass or more and 80% by mass or less in the mixture. Resin composition.   Furthermore, the carbodiimide compound is mix | blended, The compounding quantity of this carbodiimide compound is 0.5 mass part or more and 10 mass parts or less with respect to 100 mass parts of said polybutylene succinates, The resin of Claim 1 characterized by the above-mentioned. Composition. A molded product comprising the resin composition according to claim 1 or 2.