JPH0481626B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to stabilized synthetic resin compositions. Specifically, heat resistance, light resistance, and
The present invention relates to a synthetic resin composition with improved processability. [Prior art and problems] It is known that synthetic resins such as polyethylene, polypropylene, ABS, and polyvinyl chloride deteriorate due to the effects of heat and light, becoming discolored and losing mechanical strength, making them unusable. There is. In order to prevent such deterioration of synthetic resins, many additives have been used singly or in various combinations. Among these additives, phosphite compounds have been widely used because they have the advantage of imparting heat resistance and light resistance to synthetic resins and suppressing discoloration of synthetic resins. Among these phosphite compounds, tris(nonylphenyl) phosphite, diphenylisodecyl phosphite, distearylpentaerythritol diphosphite, tetraalkylbisphenol A diphosphite, etc. have relatively large effects and are prized as stabilizers for synthetic resins. was used. However, conventionally used phosphite compounds often lose their effectiveness in a relatively short time, especially outdoors or in a humid atmosphere.
Furthermore, when processing synthetic resins at high temperatures, the effect is lost, and the process is still unsatisfactory from a practical standpoint. Among these phosphite compounds, cyclic phosphite compounds are proposed to have relatively excellent light resistance and heat resistance. For example, Japanese Patent Publication No. 37-10927 proposes the use of polyalkylene glycol bisalkylene phosphite as a stabilizer for polyvinyl chloride resin, and Japanese Patent Publication No. 43-9904 proposes the use of polyalkylene glycol bisalkylene phosphite as a stabilizer for polyvinyl chloride resin. It was proposed to be used for color stabilization of cellulose resin, and was published in Japanese Patent Application Publication No. 1989-
No. 105741 proposes the use of alkylene or arylene biscyclic phosphites as light stabilizers for synthetic resins, and JP-A No. 18544/1983 proposes the use of alkylene or arylene biscyclic phosphites as light stabilizers for synthetic resins. The use of cyclic alkylene phosphite as a stabilizer for synthetic resins was proposed and
No. 81893 proposes the use of alkyl phenyl neopentylene phosphite as a stabilizer for synthetic resins, and JP-A-55-136295 proposes the use of bisneopentylene phosphite such as bisphenol A as a stabilizer for polycarbonate. It has been proposed to use it as a stabilizer, and JP-A-58-152029 proposes the use of phosphite of spirodicketal glycol as a stabilizer for synthetic resins. However, the effects of these compounds are still insufficient, especially when processing synthetic resins at high temperatures, their effects are rapidly lost, and their water resistance is also insufficient, making them unsatisfactory for practical use. Nakatsuta. [Means for Solving the Problems] In view of the current situation, the inventors of the present invention have made extensive studies and found that if an organic phosphite compound having a specific group in the molecule is added, the heat resistance, light resistance, and processability will be improved. They have found that this is a significant improvement and have completed the present invention. That is, the present invention relates to the following general formula () or ()
The present invention provides a stabilized synthetic resin composition containing an organic phosphite compound represented by: (In the formula, R ₁ and R ₂ each represent a hydrogen atom, an alkyl group, or an aryl group, and R represents an alkylene group, an arylene group, an alkylidene diarylene group, or a thiodiarylene group.) is abbreviated as P-O-CKG-O-P. Among these phosphite compounds, the compound represented by the general formula () is particularly preferred because of its great effect. The compound represented by the above general formula () or () used in the present invention will be explained in more detail. Alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tertiary-butyl, isobutyl, amyl, tertiary-amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, nonyl, decyl, undecyl, benzyl, Value chain or branched alkyl groups such as phenylethyl, phenylpropyl, cyclohexyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, docosyl, tetracosyl, triacontyl, and alkyl groups having an ether bond such as cellosolve and carbitol residues. Can be mentioned. Aryl groups include phenyl, methylphenyl, dimethylphenyl, tert-butylphenyl, di-tert-butylphenyl, octylphenyl, di-
Examples include tertiary octylphenyl, nonylphenyl, dinonylphenyl, cyclohexylphenyl, phenyl phenyl, tertiary amyl phenyl, ditertiary amyl phenyl, and the like. Alkylene groups include ethylene, propylene,
Examples include 2,2-dimethylpropylene. Examples of the arylene group, alkylidenediarylene group, or thiodiarylene group include catechol, t-butylcatechol, 2,2'-methylenebis(4-methyl-6-t-butylphenol),
2,2'-methylenebis(4-ethyl-6-t-butylphenol), 2,2'-methylenebis[4-
Methyl-6-(α-methylcyclohexyl)phenol], 2,2′-n-butylidene bis(4,6
-dimethylphenol), bis-1,1-(2'-hydroxy-3',5'-dimethylphenyl)-3,5,
5-trimethylhexane, 2,2'-cyclohexylidene bis(4-ethyl-6-t-butylphenol), 2,2'-isopropylbenzylidene-bis(4-ethyl-6-t-butylphenol),
2,2'-thiobis(4-t-butyl-6-methylphenol), 2,2'-thiobis(4-methyl-
6-t-butylphenol), 2,2'-thiobis(4,6-di-t-butylphenol), 2,2'-
Methylenebis(4-α-methylbenzyl-6-cyclohexylphenol), 2,2′-methylenebis(4-cyclohexyl-6-α-methylbenzylphenol), 2,2′-dihydroxybiphenyl, 2,2′-dihydroxy -3,3',5,5'-tetra-t-butylbiphenyl, 2,2'-dihydroxy-3,3',5,5'-tetra-t-amylbiphenyl, 2,2'-dihydroxy-3,3 ',5,
5'-tetra-t-octylbiphenyl, bis(2
-Hydroxy-3-t-butylphenyl) ether, bis(2-hydroxy-3-propylphenyl) ether, and other divalent phenols or residues obtained by removing two hydrogen groups from bisphenol. Table 1 below shows the special group P-O- of the present invention.
Specific compounds containing CKG-O-P are shown. In addition, in Table-1, the group marked + is

〔Example〕

The following examples illustrate the effects of the composition according to the present invention, but the present invention is not limited by these examples. Example 1 After blending the following formulation in a mixer for 5 minutes,
A compound was prepared using an extruder (cylinder temperature 230°C and 240°C, head die temperature 250°C, rotation speed 20 rpm). Using this compound, test pieces of 95 x 40 x 1 mm were made using an injection molding machine (cylinder temperature: 240
℃, nozzle temperature 250℃, injection pressure 475Kg/cm ² ). Thermal stability of the obtained test piece was measured in a gear oven at 170°C, and the degree of yellowness (%) of the test piece was measured using a Hunter colorimeter. Table 2 of the results
Shown below. <Composition> Polypropylene resin (Profax 6501 manufactured by Hercules) 100 parts by weight Calcium stearate 0.2 〃 Pentaerythritol tetrakis (3,5-di-
t-Butyl-4-hydroxyphenylpropionate) 0.1 〃 Phosphite compound (Table-2) 0.2 〃

【table】

[Table] Example 2 In order to examine the stabilizing effect of the phosphite compound used in the present invention during high-temperature processing, the following formulation was mixed and then extruded at 300°C. Compounds that had been extruded 1, 3, and 5 times were used to measure changes in melt index. The results are shown in Table-3. <Formulation> Polypropylene resin (Profax 6501) 100 parts by weight Calcium stearate 0.2 Pentaerythritol tetrakis (3,5-di-
Tertiary-butyl-4-hydroxyphenylpropionate) 0.1 Phosphite compound (Table 3) 0.05

[Table] Example 3 The following formulation was kneaded with a mixing roll at 150°C for 5 minutes, and then compression molded for 5 minutes at 150°C and 180 kg/cm ² to produce a sheet with a pressure of 1.0 mm. This sheet was used as a 10 x 20 mm test piece, and a thermal stability test was conducted on aluminum foil in a gear oven at a temperature of 150°C. The results are shown in Table 4. <Formulation> Polyethylene resin (HIZEX 5100E, manufactured by Mitsui Petrochemicals) 100 parts by weight Distearyl thiodipropionate 0.3 Stearyl-3,5-di-t-butyl-4-hydroxyphenylpropionate 0.1 Phosphite compound (Table -4) 0.1

[Table] Example 4 ABS resin (Styrac 200: Asahi Dow)
100 parts by weight Calcium stearate 1.0 Phosphite compound (Table 5) 0.2 1,3,5-tris(3,5-di-t-butyl-
4-Hydroxybenzyl)isocyanurate
0.1 The above formulation was extruded at 200°C to form pellets, and the pellets were then subjected to injection processing at 230°C to form test pieces. The degree of coloration of this test piece after heating in a gear oven at 135°C for 30 hours was expressed as whiteness measured with a Hunter colorimeter. Furthermore, the Izod impact value of the test piece at 20°C was also measured. In addition, after being immersed in 100℃ hot water for 24 hours,
The Izod impact value of specimens heated at 135°C for 30 hours was also measured. The results are shown in Table-5.

[Table] Example 5 50 parts by weight of poly(2,6-dimethyl-1,4-phenylene oxide) with an intrinsic viscosity of 0.56 dl/g (in chloroform at 25°C), 47.5 parts by weight of polystyrene,
Add 2.5 parts by weight of polycarbonate, 3.0 parts by weight of titanium oxide, and 0.3 parts by weight of a phosphite compound,
The mixture was thoroughly mixed using a Henschel mixer, pelletized using an extruder, and then injection molded to prepare test pieces. This test piece was placed in a gear oven at 125℃ and 100℃.
After heating for a period of time, elongation and Izot impact value retention were measured. The results are shown in Table-6.

[Table] Example 6 The following formulation was processed with a kneading roll to a thickness of 1 mm.
I created a sheet. Using this sheet, 190℃
Thermal stability and initial coloring properties were tested. We also conducted a weather resistance test using a weatherometer. The results are shown in Table-7. <Composition> Polyvinyl chloride (Pinica 37H) 100 parts by weight Di-2-ethylhexyl phthalate 45 Tricresyl phosphate 3.0 Bisphenol A diglycidyl ether
2.0 Zinc stearate 0.8 Barium stearate 0.4 Barium nonyl phenate 0.5 Sorbitan monopalmitate 3.0 Methylene bisstearylamide 0.3 Phosphite compounds (Table 7) 0.2

【table】

【table】

Claims (1)

[Scope of Claims] 1. A stabilized synthetic resin composition comprising one selected from organic phosphite compounds represented by the following general formula () or (). (In the formula, R ₁ and R ₂ each represent a hydrogen atom, an alkyl group, or an aryl group, and R represents an alkylene group, an arylene group, an alkylidene diarylene group, or a thiodiarylene group.)