JPS63221143A - Propylene resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which is freed from the phenomenon that when it is immersed in hot water the contained sorbitol derivative bleeds or exudes into the hot water and is kept suspended in it after cooling, by mixing a specified resin with a PP resin composition containing a sorbitol derivative. CONSTITUTION:A PP resin composition prepared by adding 0.001-10pts.wt. grated PP resin (C) obtained by graft-polymerizing a radical-polymerizable unsaturated compound (e.g., maleic anhydride) with a crystalline PP resin with the aid of an organic peroxide catalyst (e.g., di-t-butyl peroxide) in a hydrocarbon solvent (e.g., chlorobenzene) to a composition prepared by adding 0.01-4pts. wt. sorbitol derivative (B) of the formula (wherein R is H or a 1-18 C alkyl) to 100pts.wt. PP resin (A). This resin composition is transparent because the addition of resin makes this resin composition free from the phenomenon that when it is immersed in hot water for the purpose of sterilization or the like, the sorbitol derivative bleeds or exudes into the hot water and is kept in it after cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transparent polypropylene resin composition in which the added norbitol derivative hardly dissolves or escapes into hot water.

[Conventional technology]

Polypropylene resin has good mechanical properties, heat resistance, chemical resistance, and excellent hygiene, so it is used in food containers such as tableware, frozen dessert containers, trays, instant food containers, margarine containers, etc., and medical instruments such as syringes. Syringe,
Widely used for spitz tubes, infusion containers, cylinders, etc.

However, when used as food containers, medical instruments, etc., it is important to be able to confirm that there is no dust or other foreign matter mixed into the contents, and it is undesirable for the container to interfere with the correct color tone of the contents. .

Therefore, polypropylene resins with good transparency are desired for these uses. As a method for improving the transparency of polypropylene resin, a method of adding a sorbitol derivative represented by the general formula (2) described below is widely used.

[Problem that the invention seeks to solve]

When a polypropylene resin composition obtained by adding the above-mentioned sorbitol derivative to polypropylene/resin is immersed in hot water for purposes such as sterilization, the sorbitol derivative will elute or escape into the hot water and float in the liquid after cooling. A phenomenon occurs.

These pose health and safety issues.

As a method to solve these drawbacks, Japanese Patent Application Laid-Open No. 59-213
No. 747 and Japanese Unexamined Patent Publication No. 61-91237 have been proposed.

These disclosed methods are widely used as neutralization stabilizers for polypropylene resin compositions containing a sorbitol derivative represented by the general formula (2). The method involves adding a neutralizing stabilizer.Although these methods can prevent the sorbitol derivative represented by the general formula r from eluting or escaping into hot water to some extent, they are not yet completely satisfactory.

[Means and effects for solving the problem] The present inventors,
As a result of intensive studies to solve the above-mentioned drawbacks of polypropylene resin compositions to which a sorbitol derivative represented by general formula (1) is added, a specific compound was added to a composition consisting of a polypropylene resin and a sorbitol derivative represented by general formula (1). They discovered that confusion is effective and have completed the present invention.

That is, the present invention consists of 100 parts by weight of a polypropylene resin and 0.01 to 4 parts by weight of a sorbitol derivative represented by the general formula 1 (wherein R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms). The composition further contains 0.001 to 10 parts by weight of a grafted polypropylene resin obtained by graft polymerizing a radically polymerizable unsaturated compound to a crystalline polypropylene resin in a hydrocarbon solvent using an organic peroxide catalyst. This is a polypropylene resin composition with excellent transparency, in which the sorbitol derivative represented by the general formula I does not elute into hot water.

The polypropylene resin used in the present invention may be a propylene homopolymer, a globylene-ethylene copolymer, a propylene-α-olefin copolymer, or a mixture thereof.

The sorbitol derivative used in the present invention is represented by the above general formula (1), and specific examples include those in which R is hydrogen, methyl, ethyl, propyl, butyl, lauryl, or stearyl group.

The amount added is 0 per 100 parts by weight of polypropylene resin.
．． Addition of 0.01 to 4 parts by weight, preferably 0.02 to 2 parts by weight, has almost no effect on improvement, and adding more than 4 parts by weight does not significantly increase the effect. embossed into the mold, causing severe trouble.

The grafted polypropylene resin used in the present invention is a grafted polypropylene resin obtained by graft polymerizing a radically polymerizable unsaturated compound onto a crystalline polypropylene resin using an organic peroxide catalyst in a hydrocarbon solvent. In addition, other methods, such as mixing an organic peroxide etc. with a crystalline polypropylene resin and a radically polymerizable unsaturated compound, using an extruder,
The grafted polypropylene resin obtained by heat treatment using a Bamba IJ-mixer or the like contains a large amount of residual radically polymerizable unsaturated compounds (as a result of this, the composition of the present invention is not only colored but also has poor rigidity and This is not preferable because the effect of improving impact resistance is small.

First, the production of grafted polyolefin resin will be described.

The crystalline polypropylene resin used here may be any as long as it can be used as a propylene resin and has crystallinity.

The hydrocarbon solvents used here include aromatic hydrocarbons,
Alkyl aromatic hydrocarbons, halogenated aromatic hydrocarbons,
Aliphatic hydrocarbons, alicyclic hydrocarbons, halogenated aliphatic hydrocarbons, etc., such as benzene, toluene, xylene, mixed xylene, trimethylbenzenes, tetramethylbenzenes, ethylbenzene, cumene, cymene, chlorobenzene, Dichlorobenzene, bromobenzene, pentane, hexane, heptane, octane, cyclohexane, chloroform, carbon tetrachloride, chloroethane, 1.1-
Dichloroethane, 1.1.2.2-tetrachloroethane, 1.1-cyfuromeethane, 1.2-dibromoethane,
1.1.2.2-tetrabromoethane and the like.

These may be used alone or as a mixture of two or more.

The amount used varies depending on the type of solvent used, the degree of polymerization of the crystalline polypropylene resin, and the type and amount of the radically polymerizable unsaturated compound to be grafted, but usually the crystalline polypropylene resin is 5 to 50% by weight in the reaction mixture. , preferably 8 to 20% by weight.

As the organic peroxide used in graft polymerization, any organic peroxide used in normal radical polymerization can be used. For example, t-butyl peroxyhybarade, lauroyl peroxide, benzoyl peroxide, cyclohexanone peroxide, t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, 2 .5-dimethyl-2,5-di(1-butylperoxy)hexane, di-t-butylperoxide, 2,5-dimethyl-2,5-di(1-butylperoxy)hexine-3, etc. can give. These can be used alone or in combination of two or more.

The amount of organic peroxide charged during graft polymerization is not particularly limited, but is generally in the range of 0.01 to 100 parts by weight per 100 parts by weight of the crystalline polypropylene resin.

The reaction temperature when carrying out graft polymerization may be at least the melting temperature of the crystalline polypropylene resin, and is usually 1
The temperature is 10°C or higher. The reaction time is not particularly limited, but a range of 0.5 hours to 0.5 hours is usually sufficient.

In addition, as radically polymerizable unsaturated compounds, α, β-
Unsaturated aliphatic monocarboxylic acids and their derivatives, α, β
-Unsaturated aliphatic dicarboxylic acids and derivatives thereof, alkenylbenzenes and sono derivatives, alkenylpyridines and derivatives thereof, α-olefins, etc., and these can be used alone or in a mixture of two or more. Specific examples include acrylic acid, methacrylic acid, maleic anhydride, and itaconic anhydride.

The amount of these radically polymerizable unsaturated compounds to be used is not particularly limited, but is usually 100% of the crystalline polypropylene resin.
0.1 to 50 parts by weight, preferably 0.5 to 50 parts by weight
It is used in a range of 20 parts by weight.

The resin composition of the present invention may optionally contain other additives such as antioxidants, ultraviolet absorbers, pigments, peroxides, dispersants,
A neutralizing agent etc. can be added.

In that case, the antioxidant that can be used is tris (2,4
-di-t-butylphenyl)phosphite, 2.6-
Di-t-butyl-p-methylphenol, octadecyl-3-(4-hydroxy-3,5-di-t-butylphenyl) flobionate, tetrakis[methylene-3
-(3,5-di-t-butyl-4-hydroxyphenyl)gropionate]methane, pentaerythritol-tetrakis (β-lauryl-thiopropionate), dilaurylthiobrovineate, and the like.

As ultraviolet absorbers, 2-hydroxy-4-rb-octoxy-benzophenone, 2-(2-hydroxy-3
, 5-di-t-butyl-phenyl)-5-chlorobenzotriazole, dimethylsuccinate)-2-(4-hydroxy-2,2,6,6-tetramethyl-1-piperidyl)ethanol condensate, etc. This is a typical example.

As a peroxide, 2,5-dimethyl-2,5-bis(
Examples include t-butylperoxy)hexane, di-t-butyl perphthalate, and benzoyl peroxide, and by adding them, the melt flow index can be controlled and moldability can be improved.

The method for producing the resin composition of the present invention involves graft polymerizing a radically polymerizable unsaturated compound to a polypropylene resin, a sorbitol derivative represented by the general formula (2), and a crystalline polypropylene resin using an organic peroxide catalyst in a hydrocarbon solvent. Grafted polypropylene resin, neutralizing agents such as calcium stearate, other additives, other crystal nucleating agents, antioxidants, ultraviolet absorbers, peroxides, etc. are mixed using a Henschel mixer or other blender, and then uniformly dispersed. A method of melting and pelletizing using an extruder is used.

Since this resin composition does not elute the sorbitol derivative represented by the general formula (2) in hot water, it can be used in transparent medical instruments, food packaging, and other uses without causing any health and safety problems.

〔Example〕

The present invention will be explained in detail below using Examples and Comparative Examples.

Example 1 Crystalline polypropylene resin (
Add 3500 ml of propylene homopolymer (MI = 8) and 3500 ml of chlorobenzene, and add 3500 ml of chlorobenzene to the
After heating to 0°C, di-t-butyl peroxide 35
A solution in which 140 units of chlorobenzene was dissolved and a solution in which 50 F maleic anhydride was dissolved in 80 units of acetone were charged over a period of 4 hours. After charging, keep at 130℃ for another 3 hours
After stirring, the reaction was completed. The reaction was conducted under a nitrogen atmosphere.

After cooling, the slurry was washed with a large amount of acetone, filtered and dried to obtain a grafted polypropylene resin. The grafting rate of maleic anhydride of this resin is I
According to the R measurement, the amount was 10 parts by weight per 100 parts by weight of the polypropylene resin.

Propylene-ethylene random copolymer (melt 70
- Index 8P/min, ethylene content 4.0% by weight)
Powder 100 parts by weight K, as a non-bitol derivative
・3.2,4-di(ethylbenzylidene)sorbitol (a) 0.3 parts by weight, maleic anhydride glycol 7-tripropylene resin (ym-10) 1.0 parts by weight, calcium stearate (c) 0.1 parts by weight , 0.1 part by weight of tris(2,4-di-t-butylphenyl)phosphite as an antioxidant, dimethylsuccinate)2-(4-hydroxy2.2.2.6-tetramethyl as an ultraviolet absorber) Add 0.08 parts by weight of -1-piperidyl) ethanol condensate, mix and extrude using an ordinary extruder at a temperature of approximately 2.
Pelletized at 40°C.

The pellets 302 were placed in an autoclave with 300 ml of pure water.
After being immersed in CH and kept at 121° C. for 3 hours, the extract was filtered, and the F solution was kept at room temperature for a period of time, and suspended matter in the F solution was observed.

The evaluation of floating substances in the F solution is carried out by visual inspection, and the rating is as follows: ○ No floating substances are observed Δ Floating substances or ~ present × Floating substances are observed Injection molding was carried out using a machine at 210°C to obtain a flat plate of 160 x 80 x 2 IIm, and the haze was measured using this plate.

The results are shown in Table-1.

Example 2 In Example 1, instead of gm-10, o, ooi parts by weight of a grafted polypropylene resin (ym-0,1) having a grafting rate of maleic anhydride of 0.1 parts by weight were added, and other were pelletized and evaluated in the same manner as in Example 1.

The results are shown in Table-1.

Example 3 In Example 1, instead of gm-1o, 1.0 parts by weight of a grafted polypropylene resin (ym-0,5) having a grafting rate of maleic anhydride of 0.5 parts by weight was added,
The rest was pelletized and evaluated in the same manner as in Example 1.

The results are shown in Table-1.

Example 4 In Example 1, instead of gm-10, 1.0 parts by weight of a grafted polypropylene resin (ym-'; 5:) in which the grafting rate of maleic anhydride is a weighted part was added,
The rest was pelletized and evaluated in the same manner as in Example 1.

The results are shown in Table-1.

Example 5 In place of y m-to in Example 1, 10 parts by weight of a grafted polypropylene resin (ym-50) having a grafting ratio of maleic anhydride of about 100 parts by weight was added, and the other conditions were as in Example 1. It was pelletized in the same manner and evaluated.

The results are shown in Table-1.

Example 6゜In Example 1, 0.3 parts by weight of 1.3.2.4-dibenzylidene rubitol (b) was used instead of 1.3.2.4-di(ethylbenzylidene)sorbitol (a). The results are shown in Table 1.

Example 7 In Example 1, 0.1 part by weight of water-dispersed magnesium (A) was added in place of calcium stearate (C), but the pellets were pelletized and evaluated in the same manner as in Example 1.

The results are shown in Table-1.

Example 8 In place of 1m-10 in Example 1, 1.0 part by weight of a grafted polypropylene resin (yi-10) having a grafting rate of itaconic anhydride of 10 parts by weight was added, and the other conditions were as in Example 1. It was pelletized and evaluated in the same manner as above.

The results are shown in Table-1.

Comparative Example 1 A pelletized product was evaluated in the same manner as in Example 1 except that ym-1o was not added.

The results are shown in Table-2.

The hot water extractability of this product is significantly inferior to that of the composition of the present invention.

Comparative Example 2 In Example 1, instead of gm-1o, 0.0005 parts by weight of a grafted polypropylene resin (ym-0,1) having a grafting ratio of maleic anhydride of 0.1 parts by weight was added, and other were pelletized and evaluated in the same manner as in Example 1.

The results are shown in Table-2.

The hot water extractability of this product is inferior to that of the composition of the present invention.

Comparative Example 3゜In place of 9 m-10 in Example 1, 11 parts by weight of a grafted polypropylene resin (ym-50) having a grafting rate of maleic anhydride equal to parts by weight of the blade was added, and the other conditions were the same as in Example 1. It was pelletized and evaluated.

The results are shown in Table-2.

Although this product has good hot water extractability, its transparency is inferior to that of the composition of the present invention, and there is no point in improving transparency by adding a transparent crystal nucleating agent represented by general formula I.

Comparative Example 4 In Example I, instead of yyx-IQ, 0.001 part by weight of a grafted polypropylene resin (grx-0,05) with a craft ratio of ka o, os was added in place of yyx-IQ, and the rest were carried out. It was pelletized and evaluated in the same manner as in Example 1.

The results are shown in Table-2.

The hot water extractability of this product is inferior to that of the composition of the present invention.

Comparative Example 5 In Example 1, instead of gm-1o, 10 parts by weight of a grafted polypropylene resin (ym-60) having a grafting ratio of maleic anhydride of ω parts by weight was added, but the other conditions were the same as in Example 1. It was pelletized and evaluated.

The results are shown in Table-2.

Although this product has good hot water extractability, its transparency is inferior to that of the composition of the present invention, and there is no point in improving transparency by adding a transparent crystal nucleating agent represented by the general formula (2).

Comparative Example 6゜Pellets were prepared in the same manner as in Example 1, except that 0.1 part by weight of calcium stearyl lactate (e) was added instead of calcium stearate (C) in Example 1, and g m-1o was not added. and evaluated it.

The results are shown in Table-2.

The hot water extractability of this product is significantly inferior to that of the composition of the present invention.

Comparative Example 7゜Pellets were prepared in the same manner as in Example 1 except that 0.1 part by weight of magnesium hydroxide (d) was added instead of calcium stearate (C) in Example 1, and gm-to was not added. and evaluated it.

The results are shown in Table-2.

The hot water extractability of this product is significantly inferior to that of the composition of the present invention.

Comparative Example 8゜In Example 1, 51 m-10 was not added, and the amount of 1-3.2.4-di(ethylpe/zylidene)nlubitol (a) was reduced to 0.1 parts by weight. , otherwise pelletized and evaluated in the same manner as in Example 1.

The results are shown in Table-2.

The hot water extractability of this product is inferior to that of the composition of the present invention.

(Notes for Tables 1 and 2) PP...Polypropylene resin sorbitol derivative-a...1,3,2,4-di(ethylbenzylidene) Sorbitol-b...1,3,2,4-dibenzylidene Sorbitol additive -〇...Calcium stearate-d...Magnesium hydroxide-e...Calcium stearate lactate y m -x...Maleic anhydride grafted polypropylene resin graft ratio X parts by weight gi-x...・Itaconic anhydride gra 7 to polypropylene resin grafting ratio x parts by weight

Claims (1)

[Claims] 100 parts by weight of polypropylene resin and general formula I ▲mathematical formula,
There are chemical formulas, tables, etc. ▼ I (In the formula, R represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.) To a composition consisting of 0.01 to 4 parts by weight of a sorbitol derivative, , a polypropylene comprising 0.001 to 10 parts by weight of a grafted polypropylene resin obtained by graft polymerizing a radically polymerizable unsaturated compound to a crystalline polypropylene resin in a hydrocarbon solvent using an organic peroxide catalyst. Resin composition.