JPS60208341A - Polypropylene composition - Google Patents

Abstract

PURPOSE:To produce a polypropylene composition resistant to the discoloration with radiation, especially gamma-ray radiation, and to the lowering of physical properties caused by aged deterioration after irradiation, by compounding a polypropylene resin with a phosphite polycondensation product of pentaerythritol and hydrogenated bisphenol A. CONSTITUTION:(A) 100pts.(wt.) of a polypropylene is compounded with (B) 0.01- 1pt., preferably 0.05-0.5pts. of a phosphite polycondensation product of pentaerythritol and hydrogenated bisphenol A, preferably the compound of formula I (1<=n<=1,000) and (C1) a symmetrical triaryl phosphite of formula II (R2 is tert-butyl, 1,1-dimethyl propyl, etc.; one of R2 and R3 is H and the other is H, methyl, tert-butyl, etc.), preferably tris(2,4-di-tert-butyl-phenyl) phosphite, (C2) a phenolic antioxidant preferably containing isocyanate group in the molecule, and (C3) one or more hindered-amine photo-stabilizers. The amount of C1 is preferably 0.01-0.5pts., and that of C2 and/or C3 is 0.01-1pt.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polypropylene compositions with improved radiation resistance, which are resistant to 711. 1. Avoid discoloration and long-term damage. The object of the present invention is to provide a polypropylene composition with significantly less deterioration in physical properties.

Traditionally, polypropylene has been used in various packaging materials.

Films or mediums are effectively used as disposable medical instruments such as syringes. Such polypropylene is blended with various additives such as stabilizers and modifiers depending on the purpose of use, in order to provide stability during molding processing and practical durability of the molded product. However, products used for food and crop packaging containers, films, and disposable medical devices are generally irradiated with radiation (generally gamma rays) for sterilization and insecticidal purposes, but in the case of polypropylene, There are problems with discoloration and decreased mechanical strength.

Gamma ray sterilization is a safer and more effective method for ships and medical equipment, but the standard sterilization amount is 2, 5.
When irradiated with γ-rays using Mrad, there is a significant decrease in mechanical strength and discoloration due to decomposition and deterioration of polypropylene.

In order to improve these problems, for example, in polypropylene, a phenolic thread antioxidant containing an isocyanurate group and a thiosynchronous system are blended and combined (Kikukaian 55-1
No. 37135).

Adding triarylphosphite yarn antioxidant (41!l 1987-179234) or heterocyclic hindered amine compound and 1.3.5
-tris(3-hydroxy2,6-cy)fru4-
It has been proposed to mix esters with (alkylbenzyl) incyanurate (Japanese Patent Publication No. 42638/1983).

According to these methods, it is possible to prevent discoloration of cabolybrobylene due to γ-ray irradiation and deterioration of physical properties immediately after γ-ray irradiation, as described above. However, since such polypropylene irradiation with all gamma rays has not sufficiently improved the physical property deterioration after a long period of time and the elongation deterioration due to post-irradiation heating treatment, there is a concern that the polypropylene will become brittle in practical use. .

The present inventors have conducted various studies on polypropylene compositions that exhibit less discoloration due to radiation irradiation and less deterioration of physical properties due to changes over time after radiation irradiation, and have found that the above problems can be solved by incorporating additives that are effective. The present invention has now been completed.

That is, the present invention is a polypropylene composition containing a phosphite polycondensate of pentaerythritol and water-cooled bisphenol A.

The boria pyrene used in the present invention is a crystalline polypropylene generally used as a material for molded products, a crystalline comonomer mainly composed of propylene, or a blend with other polymers mainly composed of crystalline polypropylene. .

Examples include a crystalline copolymer mainly composed of propylene, an ethylene-propylene random copolymer, an ethylene-propylene block copolymer, or a propylene-dobutene copolymer. In addition, as a blend with other polymers mainly consisting of crystalline polypropylene,
For example, high-density or low-density polyethylene, polyvinyl acetate, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer.

Examples include polybutene-1, poly2-methylpentene-1, and the like.

In the present invention, it is extremely important to blend a phosphite polycondensate of pentaerythritol and hydrogenated bisphenol A into the above-mentioned polypropylene. γ as if
Denaturation and deterioration of physical properties after radiation irradiation are suppressed.

A phosphite polycondensate of pentaerythritol and hydrogenated bisphenol A is, for example, 1 m of pentaerythritol.
O! and hydrogenated bisphenol A (2,2-bis(4'-hydroxycyclohexyl)propane 1mO! and triphenylphosphite 2000mO) with a molecular weight of about 10,000, etc. Among these, those expressed by the formula (where l<n<1000) are preferably used.

Pentaerythritol and hydrogenated bisphenol A mentioned above
The blending amount of the phosphite polycondensate is 001 to 11 Dobe for 100i of holiflobylene, and 005 for pancreatic acid.
~051kk autopsy is illuminating. If the amount is lower than this range, the reduction in the physical properties of the gamma-ray illuminated bales will be insufficiently suppressed, and if too large a quantity is added, it will induce a decrease in transparency and surface viscosity.

The composition of the present invention includes the addition of known stabilizers and modifiers such as heat stabilizers, which are used to impart stability during molding processing and practical durability of molded products to the above additives. agent is added.

Among others, at least one selected from the following phosphite-type combinations of pentaerythritol and hydrogenated bisphenol A, triarylphosphites, phenolic antioxidants, and hindered amine light stabilizers were distributed. Phosphite K 417 compound of pentaerythritol and water bisphenol A.

and triarylphosphite, phenolic fertilization prevention wholesale I and hindered amine light stabilizer I.
A composition containing at least 14ill of C is preferably used because it causes very little deterioration in color appearance, quality, and quality due to gamma polishing.

triarylphosphite, 24 (wherein, R1 represents tert-butyl, 1,1-dimethylfurobyl, cyclohexyl or phenyl group, R2 and R3
Among them, the - force is a hydrogen atom, and the other force is a hydrogen atom, methyl, tert-butyl, 1,1-dimethylfurobyl, cyclohexyl, or phenyl^). Phosphite is used. Especially NRIs
is a tertiary butyl group, or one of R2 and R3 is a hydrogen atom.

Tris-(2,5-di-tert-butylphenyl) phosphite is preferably used as a compound in which a hydrogen atom or a tertiary funal group is bonded.

The above-mentioned blend of triarylphosphite is generally 0.01 to 100 mJi parts of polypropylene.
The amount is 0.5 parts by weight, preferably 0.05 to 0.2 parts by weight. If the amount of triarylphosphite blended is too small, stability during molding processing will decrease. Father added too much. In this case, the stability during molding process decreases, and the additive bleeds out from the surface of the molded product, which is not favorable.

As a phenolic antioxidant, for example, 1.3.5
-tri(3,5-di-tert-butyl-4-oxybenzyl)-2,4,6-1 methylbenzene.

1.3.5-) Lis-(3,5-di-tertiary phthyl-4-
oxybenzyl)-isocyanurate, 3 r 5-
Sea p) Tamafutyl-4-oxybenzyl-phosphonic acid-
Diethyl ester, l, 3.5-)! jSusu-4-tert-phthyl-3-hydroxy-2,6-dimethylbenzyl)
Mention may be made of oxybenzyl-aromatic compounds such as isocyanurates, among others 1. :(,5-tris(3
-Hydroxy-2,6-dimethe-4-tert-butyl benzyl) innoanule-l.

Alternatively, phenolic antioxidants containing in cyanurate foundations in the If(, ej) structure, such as tris(3,5-di-tert-fulfur-4-hydroxybenzyl)isocyanurate, are used.

Hintard Amin Itomitsu! i'irx agents, such as 4-benzoyloxy-2,2,6,fi-tetramethylpiperidine, bis=(2,2,fi,h-tetramethyl-4-N-methylpiperidine)sebaque;・.

Di(1,2,2,6,6-bentamether-4-piperidyl)-2-n-butyl-2J3.5-di-tert-butyl-4-hydroxybenzyl)malonate, bis-(2゜2.6.6 Examples thereof include -tetramethyl-4-carbonyloxyhiberidi/)-P-dimethylbenzyl, among which di(2,2,6,6-tetramethyl-4-piperidyl)sebacate is preferably used.

±MeL phenol pre-forming inhibitors and hindered amine light stabilizers can be blended individually or in combination, but in either case, the blending amount is generally 0.01 to 1 part by weight. , preferably 002-02 intoxication. If the amount of the above additive is too small, the thermal stability during molding will decrease. - If the force is too large, the processability during molding will deteriorate and the additive will bleed out from the molded product, so this is not desirable.

These additives can be blended into hollybrobylene by a commonly used blending method. For example, a suitable method is to add additives to holypropylene, premix it, and then mix it in an extruder.

In addition to the above-mentioned additives, a thionidel antioxidant, a neutralizing agent (dispersing agent), a lubricant, a clarifying agent, a nucleating agent, etc. can be added to the holiflobyrene-containing drink of wood ψ1.

As mentioned above, the polypropylene Kazunari of the present invention has very little discoloration due to radiation irradiation, has little property deterioration due to changes over time after irradiation, and has little elongation deterioration in size, and is suitable for medical wrappings or food packaging systems. is suitable as a nuclear reactor-related phase classification.

The discoloration and inhibition of phosphorescence of phoriflopyrene products due to radiation will be shown in Examples below.

In Examples 1 to 12, the stabilizer symbols are as follows.

A: Phosphite 714 compound of pentaerythritol/water-cooled bisphenol A (manufactured by Johoku Kagaku Kogyo Co., Ltd., trade name J P I-1 3800)
゜molecules approximately 10,000) B Nidris (2,4-di-tert-butylphenyl) phosphite C: 1.3.5-4 Lis (3-hydroxy-2,6-
Dimethel=4-tert-butyl-benzino)isocyanurate D ditris(3,5-di-tert-butyl-4-hydroxybenzyl)in cyanurate E: 1.3. s-Tris [β(4-hydroxy-3,
5-Ditertiary phthyl phenyl) fropionyloxyethyl] isocyanurate F di-(2,2,Fi, 6-tetramethyl-4-
Piperidyl) Sebacate G: Jimirisu Ruteoji 70 Bio-Assemblage 1-i: 2
, 6-di-tert-butyl-4-methylphenol I: Tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyhydrocinnamate)] Mt IJk in the methane valley example, V ~ adjustment, for testing The sample preparation and effect testing methods were as follows.

l) Pace polymer and additive compound ethylene content 201 [weight, melt index (A
STM-f)-1238, hereinafter abbreviated as MI), 20 parts of ethylene-propylene lantum co-i total 1 (10M7 parts by weight and additives in the proportions shown in Table 1).

0.15 parts by weight of a neutralizing agent (calcium stearyl lactate), 0.30 parts by weight of a clarifying agent (1,3,2,4-di(methylbenzylidene)nlubitol), and 0.05 parts by weight of a lubricant (oleic acid). Blend and premix with a Henschel mixer. 2) Belet ratio: The mixture (υ) is made into pellets using a Chuo Kikai 40111ψ extruder at a resin temperature of 260°C.

3) Preparation of test pieces The above pellets (2) were subjected to the tensile test piece, Izot test piece and yellowing test described in 6) using a general molding condition (250°C) using an 8oz injection molding machine manufactured by Japan Steel Works. Create pieces. (8) 4) Radiation Irradiation Using a cobalt 60 gamma ray irradiation device, the pellet (2) and test piece (8) were irradiated at a dose rate of 2 Mrad/h. OMra
d to compare.

5) Post-irradiation heating treatment and conditioning The post-irradiation heating treatment is performed at 60°C for 30 days in a Trust Oven manufactured by Toyo Kagaku (blank replacement amount: 1 Volume/ml). The pellets (2) and test pieces (8) after each treatment are subjected to the test (6) after conditioning them at 23°G for 48 hours or more.

6) The effect was M I (ASTM-1) 1238 230'Cy on pellets (2) and test pieces (8) together with test method comparison samples.
/m1n) Yellowness YI (Yellowness 1nd)
ex ASTM I) 1925 test piece 5flX]00
Tensile test (ASTM
D638) and Izod impact test (ASTM D25)
6. (23°C with a notch)

Examples 1 to 12 The additives of the present invention were prepared by using tF in accordance with the above-mentioned Hara Kirisashi and '7] method. Table 1 shows the blinded results of yellowing Yl and MI Oki 1 constant, Izot S Hayabusa and tensile test by heating treatment before and after γ-ray irradiation, with 41 combinations as experiment numbers 1 to 5. It's a show.

Incidentally, those that do not use the additive combination of the present invention, that is, the radiation-resistant holibrobelene compositions described above, which have been conventionally used, are shown in Experiment No. 6 to IO, and the general holiflobylene composition a is shown in Experiment No. 11. Table 1 also lists the lees beds compared as No. 12.

Procedural amendment May 1980, IC Date Kazuo Wakasugi, Commissioner of the Patent Office 1, Indication of the case: Japanese Patent Application No. 1983-63197 2, Title of the invention: Polypropylene composition 3, Relationship with the person making the amendment: Patent application Address: 1-1-4, Mikage-cho, Tokuyama-shi, Yamaguchi Prefecture; Date of amendment order: Voluntary action: 5; Number of inventions to be increased by amendment: None: 6; explanation J
Column 7, Contents of amendment 1) The "Claims" of the specification are amended as shown in the attached sheet.

2) R 25 Mrad on the third line from the bottom of page 3 of the specification.
J to r 2. FI Mrad J Ic correction.

3) In the third line from the bottom of page 5, "propylene-]-butene copolymer" is corrected to "propylene-butene-1 copolymer."

4) On page 7, line 9, “001 to 1 part by weight, especially 005
~05 parts by weight'' rO, 01 to 1 parts by weight, especially 0.05 parts by weight
Corrected to "~0.5 Serious Injury Part."

5) On page 9, line 4, r(2,5-di-tert-butylphenyl) J was corrected to "r(2,4-di-tert-butylphenyl)".

6) rl from page 9, line 5 from the bottom to page 10, line 3,
3.5-tri(3,5-di-tert-butyl-4-oxybenzyl)-2,4,6-1-limethylbenzene, 1.
3.5-) Lis-(3,5-di-tert-butyl-4-oxybenzyl)-isocyanurate), 3.5-di-tert-butyl-4-oxybenzyl-phosphonic acid diethyl ester, 1.3 .5-) Lis-(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate, unaoxybenzyl...'' triphthyl-4-hydroxybenzyl) 2.4゜6-trimethylbenzene, 1.3.5-
) Lis(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 3,5-di-tert-butyl-4
-Hydroxybenzyl-phosphone H-diethyl ester, hydroxybenzyl of 1,3,5-tris(3-hydroxy2,6-dimethyl-4-tert-butylbenzyl)in cyanurate...''.

7) After “or” on page 10, line 7, “1°3.5
- Insert J.

8) [Bis-(2,2
, 6, fi-tetramethyl-4-N-methylpiperidine) sebacate" is corrected to [bis(2,2°6.6-tetramethyl-4-piperidyl) sebacate, ].

9) Page 10, lines 6 to 2 from the bottom [G N, 2, 2
．． 6.6-bentamethyl-4-piperidyl)-2-n-
Butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate, bis-(2,2,6,6-tetramethyl-4-carbonyloxypiperidino-P-dimethylbenzyl)" deleted do.

10) “G” (2,2°6.
6-...Hot'' [vinny (2, 2, 6, 6, -...
Correct to the month.

11) On page 11, line 1, "Sevakeit" is corrected to "Sevaketo".

12) "001-1 part by weight, preferably 002-02" on page 11, line 6 is corrected to 1001-1 part by weight, preferably 002-0.2.

13) Correct "thionidel system" to "thioether system" in the third line at the bottom of page 11.

14) Change “inhibitory change” in line 7 of page 12 to “physical property change”
K Correct.

15) On page 12, line 4 from the bottom, “-4-tertiary butyl-
" is corrected to "-4-tertiary butyl-".

16) “G (2,2°6.
6-tetramethyl-4-piperidyl) sebacate” [
Bis(2,2,fi,6-tetramethyl-4-piperidyl) sebacate JK Correct.

7) On page 13, line 8, [-4-hydroxyhydrocinnamate)]methane J is corrected to "r-4-hydroxy-phenyl)propionate comethane."

18) On page 13, line 13, r20'at*J is corrected to ``2°0 times %1.''

19) r on page 13, line 14 (ASTM-D-123
8. Insert [230°C 2/10 decoy] after J.

20) In the first line from the bottom of page 13, "(oleic acid)" is corrected to "(oleic acid amide)" by JK.

21) Correct "pellet ratio" on page 14, line 3 to "pelletization".

22) rt/10-” “2/Edition” on page 15, line 3.
Correct.

24) Correct "Hindered amine type" in the Additive type column of Table 1 of the same Article 16 to correct ``Hindered amine type or thioether type IK.

8. List of attached documents One or more attached sheets showing the content of amendments to the scope of claims Attachment The scope of claims is amended as follows.

5) A polypropylene composition containing a phosphite polycondensate of pentaerythritol and hydrogenated bisphenol A. 2) A phosphite polycondensate of pentaerythritol and hydrogenated bisphenol A having the formula (where 1≦n≦ 10([) 3) The phosphite polycondensate of pentaerythritol and hydrogenated bisphenol A is present in an amount of 0.01 to 100 parts by weight of polypropylene 62. 4) at least one selected from triarylphosphite, phenolic antioxidant, and hindered amine light stabilizer; 5) The polypropylene composition according to claim 1, in which one type of triarylphosphite is blended with the formula (wherein, Ro is tert-butyl, 1,1-dimethylpropyl, cyclohexyl, or phenyl group: R2 and R3 is a symmetrical triarylphosphite represented by at least one hydrogen atom and the other methyl, tert-butyl, 1,1-dimethylpropyl, cyclohexyl, or phenyl group. Polypropylene composition town described in item 4

Claims (1)

[Scope of Claims] 1) A polypropylene composition containing a phosphite condensate of pentaerythritol and hydrogenated bisphenol A; 2) A phosphite condensate of pentaerythritol and hydrogenated bisphenol A having the formula (formula (1≦n≦1000), between the first item and the other, the dC-based hollybrobide compound 3) pentaerythritol water-cooled bisphenol A and a small phosphite finely divided into polypropylene 4) Triarylphosphite, phenolic thread antioxidant, and hindered amine thread The difference is t from nine stabilizers.
(5) The polypropylene composition containing at least 14 triarylphosphites has the formula (wherein RH is tertiary phthalate, ,
Cyclohexyl- or phenyl group: R2 and R3 are at least one hydrogen atom and the other is methyl, tertiary phthyl, 11-dimethylfuroyl, cyclohexyl or phenyl group) The polypropylene composition described in claim 4, which is a triarylphosphite of I-inhibited type.