JPH0615646B2 - Stabilized polypropylene composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stabilized polypropylene composition, particularly to prevent contact deterioration with a metal such as copper, and to prepare a mixture of an inorganic filler and a pigment. The present invention relates to a thermoplastic polypropylene resin composition which is prevented from deterioration.

[Conventional technology and its problems]

Polypropylene is widely used in industry as a general-purpose plastic, but copper, iron, cobalt, nickel,
It has the drawback that it deteriorates when it comes into contact with chromium, aluminum, etc., especially copper. As a solution to this problem, there is a method of mixing triazoles, tetrazoles, substituted hydrazines, malonic acid amides, oxalic acid amides, and the like.

In addition, polypropylene has the drawback of easily being oxidatively deteriorated by adding inorganic fillers and pigments such as calcium carbonate, aluminum hydroxide and antimony oxide. As a solution to this problem, sterically hindered phenols, phosphite ester-based compounds, etc. There is known a method of mixing the stabilizers.

The present invention has found an improved composition which is different from these known methods and is capable of preventing metal contact deterioration and oxidative deterioration of polypropylene.

[Means for solving problems]

The present invention has variously investigated the utilization of the unique property of the cyanato group of the compound having a cyanato group (-OCN). As a result, the addition of the compound having a cyanato group to polypropylenes prevents the metal-catalyzed deterioration of polypropylene and oxidation. It was found that the stability was greatly improved.

That is, according to the present invention, polypropylene contains one or more cyanato groups in the molecule (1) monofunctional or polyfunctional cyanate ester or one or more cyanato groups in the molecule (2). 0.01 to 10% by weight of the cyanate ester prepolymer (hereinafter, simply referred to as "cyanate")
It is a stabilized polypropylene composition formed by mixing, and further provides a composition in which an inorganic filler or a pigment is blended as polypropylene, in which oxidative deterioration is largely prevented.

The present invention will be described below.

The polypropylene of the present invention is a normal polypropylene, a high to low density polypropylene, a copolymer of propylene and other olefins, a composition obtained by mixing polypropylene with an elastomer such as an olefin elastomer, and further silica. And a nucleating agent such as a stabilizer, a flame retardant, an ultraviolet absorber, and the like are appropriately added.

The inorganic filler or pigment of the present invention includes calcium carbonate,
Aluminum hydroxide, magnesium hydroxide, talc, clay, mica, antimony oxide, iron oxide, gypsum, copper, iron,
Inorganic fillers such as cobalt, nickel, chromium and aluminum, titanium oxide, iron oxide, carbon black and other pigments. The addition amount to the polypropylene resin is a usual addition amount, and is about 5 to 70% in the case of an inorganic filler and 0.01 to 5% in the case of a pigment.

Suitable as the (1) monofunctional or polyfunctional cyanate ester containing at least one cyanato group in the molecule of the present invention is the following general formula (1): R (OCN) _m (1) (M in the formula is an integer of 1 or more and usually 5 or less, R ₂ is an aromatic organic group, and the cyanato group is bonded to an aromatic ring of the organic group) Is. Specific examples include monocyanatobenzene and P-tert.
-Alkyl cyanatobenzene such as butyl cyanatobenzene, monocyanatonaphthalene, 1,3- or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, 1,3-, 1,4-,
1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1,3,6-
Tricyanatonaphthalene, 4,4'-dicyanatobiphenyl, bis (4-dicyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dichloro-4) -Cyanatophenyl) propane, 2,2-bis (3,5-
Dibromo-4-cyanatophenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) sulfone, tris (4-cyanatophenyl) phosphite , Tris (4-cyanatophenyl) phosphate, and cyanate ester obtained by the reaction of novolac with cyanogen halide. In addition to these
, Same 43-18468, same 44-4791, same 45-11712, same 46-4111
2, cyanate esters described in JP-A No. 47-26853 and JP-A No. 51-63149 can also be used.

Further, a cyanato group is formed in a molecule obtained by polymerizing the above-mentioned polyfunctional cyanate ester in the presence of a mineral acid, a Lewis acid, a salt such as sodium carbonate or lithium chloride, or a phosphate ester such as tributylphosphine. Contains one or more (2). It can be used as the cyanate ester prepolymer, and can also be used as a prepolymer with an amine.

Here, one or more cyanato groups are contained in the molecule described above (2). A monomer having two cyanato groups, for example, a cyanate ester from bisphenol A [= 2,2-bis (4-cyanatophenyl)]
[Propane] will be described.

First, the cyanato group (—O—C≡N) is the cyan moiety (C≡ of three cyanato groups (C≡N) due to the above Lewis acid or the like.
N) is bonded to form a compound in which a sym-triazine ring is formed.

As a result, a trifunctional cyanate ester compound in which three residues having a cyanato group are bonded to carbon C of the sym-triazine ring via —O— is obtained.

Furthermore, one of the cyanato groups of this compound combines with two other cyanato groups to form a sym-triazine ring as well.

Since this reaction proceeds randomly, 3 monomers (1 sym-triazine ring; 3 functional), 5 (2 sym-triazine rings; 4 functional), 7 (sym-triazine ring)
(3, 6-functional) ..., and a mixture of odd-numbered sym-triazine rings while forming a sym-triazine ring is obtained.

The molecular weight of these cyanate ester prepolymers can be controlled by the degree of reaction, but the number average molecular weight is generally 300 to 1,000.

The compounding amount of the cyanate of the present invention with respect to polypropylene described above is in the range of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, and particularly 0.1 to 3% by weight, and the monomer is more functional group (-) per unit amount. It is more effective because it has a large number of OCN groups. Further, in the case of a polypropylene composition containing an inorganic filler or a pigment, it is preferable to select from a range of 0.1 to 10% by weight of the inorganic filler or the pigments.

If the amount added is less than 0.01%, the effect of preventing contact deterioration with metals and the effect of preventing thermal oxidative deterioration of inorganic fillers and pigment blends are insufficient. It has a remarkable effect in preventing contact deterioration and thermal oxidation deterioration.
It is not preferable because other properties such as a decrease in elongation of polypropylene are impaired. Further, as described above, the effect of the present invention is by cyanato group, additive agents to react with the functional groups - for example, -OH, -COOH, -NH _2, -SH
When it is necessary to add a compound having, etc., it is preferable to avoid adding these compounds at the same time as the cyanate.

As a method of mixing cyanate with polypropylene,
There is no particular limitation as long as it is a method in which the cyanate is uniformly dispersed, and a conventional method, a method of mixing by a blender or other means and pelletizing with an extruder, a method of mixing with polypropylene as a solution and drying, a kneader, a Henschel mixer Such as mixing and extruding and using as pellets, and in the case of containing an inorganic filler or pigment, a method of mixing the inorganic filler or the like with cyanate in advance and extruding this with polypropylene, a high-concentration masterbatch A method such as a masterbatch method for producing and mixing the same is also suitable, and in the case of an extruder, the extrusion conditions of polypropylene can be used as they are as the mixing conditions. In other cases, the mixing may be carried out at room temperature or under heating, and the mixing time depends on the temperature, but at a temperature of about 200 ° C., the effect of the present invention can be sufficiently retained even by mixing for about 2 to 3 hours. However, a method in which the reaction of cyanate is smaller is more preferable.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples and the like. In the examples and the like, parts are parts by weight unless otherwise specified.

Examples-1, 2 Polypropylene resin (manufactured by Chisso Petrochemical Co., Ltd., trade name;
K-1016) and (Mitsui Toatsu Co., Ltd., trade name; Nobren
BJHH-M), 2,2-bis (4-cyanatophenyl) propane (hereinafter referred to as BPA-CN) was added in the amount shown in Table 1, and pelletized by an extruder at a temperature of 180 to 200 ° C. did.

The pellets were injection-molded to form a transparent white plate having a size of 50 × 50 mm and a thickness of 1 mm.

A copper foil having a thickness of 70 μm was brought into contact with this flat plate and placed in a constant temperature bath at 150 ° C. for a deterioration test.

The results are shown in Table 1.

Comparative Example-1 The same procedure was performed as in Example-1, except that 2,2-bis (4-cyanatophenyl) propane was not used.

The test results are shown in Table 1.

Reference Examples-1 to 4 The same as Example 1 except that a commercially available copper damage inhibitor and other additives were used in the amounts shown in Table 1. The results are shown in Table 1.

Example-3 To the same polypropylene as in Example-1, the inorganic filler and BPA-CN were added in the amounts shown in Table 2, and the temperature was 180 to 200 ° C.
The same test variation was prepared by making pellets with the extruder.

The flat plate was put in a constant temperature bath at 150 ° C. and subjected to a deterioration test.
The results are shown in Table 2.

Comparative Example-2 The same procedure was performed as in Example-3, except that BPA-CN was not used and that other stabilizers were added. The test results are shown in Table 2.

Example-4 and Comparative Example-3 Intrinsic viscosity [η] = 1.80 (at 135 ° C, tetrahydrofuran solution) obtained by using a Ziegler-Natta type catalyst 10
2.0 parts and 5.0 parts of monocyanatobenzene (hereinafter, referred to as P-CN) were added to 0 parts, respectively, and kneaded with a roll at 180 ° C. for 10 minutes.

This mixture is press-molded to form a flat plate with a thickness of 1.5 mm, and the flat plate is placed as it is and with the flat plate in contact with a 35 μm-thick copper foil in a gear oven at 150 ° C. until the flat plate turns yellow. I checked the time.

The results are shown in Table 3.

For comparison, a deterioration test was also performed on a sample not using P-CN. The results are also shown in Table 3.

Example-5 and Comparative Example-4 1,4-dicyanatobenzene (hereinafter referred to as PD-CN) in acetone was mixed with talc, calcium carbonate, and aluminum hydroxide, and then dried at 80 ° C. for 10 minutes. Then P
An inorganic filler having 1.2 parts of D-CN attached was prepared.

This inorganic filler was mixed with the same polypropylene resin as used in Example-1 in a weight ratio of 1: 1 and pelletized with an extruder at 190 ° C., and injection-molded to obtain 50 mm × 50 mm.
A flat plate test piece having a thickness of 1.0 mm was prepared.

This flat plate was put in a gear oven at 150 ° C and subjected to a heat deterioration test. The results are shown in Table 4.

For comparison, a deterioration test was also performed on the sample without PD-CN. The results are also shown in Table 4.

Example-6 and Comparative Example-5 100 parts of the same polypropylene resin as used in Example-1 was mixed with 1 part of BPA-CN and 1.5 parts of carbon black, and the mixture was pelletized with an extruder at a temperature of 180 to 200 ° C. Was injection molded to prepare a black 50 mm x 50 mm flat plate test piece with a thickness of 1.0 mm.

This flat plate was put in a gear oven at 150 ° C and subjected to a heat deterioration test. The results are shown in Table 4.

For comparison, the same was applied to those not using BPA-CN. The results are also shown in Table 4.

[Operations and Effects of the Invention] As is clear from the above detailed description and Examples, the composition of the present invention exerts an extremely excellent effect as a copper damage inhibitor, and also exhibits transparency of a molded article. It can be seen that there is almost no deterioration, and the composition exhibits an excellent effect even in the case of oxidative deterioration due to the filler or the pigment, and that it is an extremely excellent composition.

Claims (2)

[Claims] 1. A polypropylene containing at least one cyanato group in the molecule (1). It contains monofunctional or polyfunctional cyanate ester or one or more cyanato group in the molecule (2). 0.01-10 of the cyanate ester prepolymer
Stabilized polypropylene composition obtained by mixing by weight 2. The polypropylene composition according to claim 1, wherein the polypropylene contains an inorganic filler or a pigment.