JP2581703B2 - Halogen-containing resin composition containing zinc glycine - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a novel heat-stable halogen-containing resin composition containing zinc glycine. More specifically, based on the remarkable correlation between the particle size of zinc glycine to be incorporated into the halogen-containing resin and the effect of thermal stability, zinc glycine finely ground to an average particle size of 10 μm or less by appropriate means. It is an object of the present invention to obtain a halogen-containing resin composition having excellent heat stability by adjusting the composition.

2. Description of the Related Art In general, halogen-containing resins, particularly vinyl chloride resins, are liable to be degraded by the action of heat and light, resulting in discoloration, decomposition, reduction in mechanical strength, change in appearance, reduction in molded products, and the like. Has a problem that the commercial value of the product is lowered and the product cannot be used for a long time.

JP-A-54-55,047 discloses that a metal salt of an amino acid or a derivative thereof is blended with a vinyl chloride resin to obtain a composition having excellent heat stability. It has been revealed that amino acid metal salts or derivatives thereof are considerably excellent not only in thermal stability but also in transparency and processability. As the amino acid metal salts, calcium salts, zinc salts, and the like are used, and have advantages such as extremely long stabilization time, extremely short dehydrochlorination rate, and relatively little physiological toxicity.

However, a person skilled in the art strives to further improve the technical content disclosed herein, and has developed a halogen-containing resin composition obtained by blending zinc glycine and / or zinc glutamate with a basic organic acid zinc compound. What has been developed is as specified in JP-A-63-301,248. Further, as for zinc glycine or basic zinc glycine, the thermal stability effect on the halogen-containing resin by the production method is remarkably different as described in JP-A-1-45,450.

That is, when 100 parts by weight of a halogen-containing resin is mixed with 0.1 to 10 parts by weight of glycine zinc mixed or mixed with an extremely small amount of added water, or glycine adjusted with a large amount of water, It shows significantly improved thermal stability as compared with the case where zinc or basic zinc glycine is blended, and further improves the prevention of discoloration by simultaneously blending a basic organic acid zinc compound.

Problems to be Solved by the Present Invention The present inventors have found that the thermal stability effect of zinc glycine to be blended is closely related to the particle size.
Conventionally, it is a well-known fact that, when compounded with a halogen-containing resin, a substance that does not melt or dissolve and disperse must be finely ground. Further, it is common to appropriately select a pulverizing means depending on the type of the compound to obtain an intended product.

Regarding the adjustment of zinc glycine, for example, BWLow, FL
Hirshfeld, FMRichards et al., J. Am. Chem. Soc. 81, 4412 (1
959), 1 mole of glycine, zinc oxide
A typical method is to dissolve and recrystallize a solution by boiling 0.5 mol of water in a large amount of water, but a double decomposition method is also known.

However, the crystal grains of zinc glycine obtained by any method are too large to be blended as it is. In fact, even in experiments of thermal stability, if crystal grains are used as obtained, the effect is poor, and the purpose of blending cannot be achieved. To improve the thermal stability effect,
The zinc glycine must be ground into fine particles.
In this respect, it is desirable that the composition is as fine as possible and that the particle size distribution is not biased.

Means for Solving the ProblemsThe present inventors have accumulated various tests on the thermal stabilizing effect of zinc glycine, and as a result, it is not enough to pay attention to the relationship between the average particle size and the thermal stabilizing effect which are generally performed. It was found to be inadequate and the relationship with the particle size distribution was even more important. That is, it has been found that not only the average particle size is 10 μm or less, but also that the ratio of particles having a size of 10 μm or more is as small as possible has a great effect on the improvement of the thermal stabilizing effect.

In the present invention, the effect on the thermal stability of zinc glycine is preferably such that the average particle size is 10 μm or less, and at least 10 μm.
Those having a particle size of not more than 70 μm are preferred. For this purpose, pulverization is carried out using a commercially available fine pulverizer, for example, an impact pulverizer, a vibration ball mill, a jet pulverizer, a tower pulverizer, a colloid mill, a wet pulverizer and the like. In order to obtain the target particle size, it is necessary to select such a pulverizer, repeat pulverization, and extend the pulverization time. Occasionally, a pulverizer may be used in combination, for example, an impact pulverizer, a wet pulverizer, or a jet pulverizer.

It should be noted that the use of a substance that is usually blended with pulverized zinc glycine having an average particle diameter of 10 μm or less does not inhibit the effect of the present invention at all, but rather further promotes the effect.

For example, organometallic compounds, organic phosphites, antioxidants, β-diketone compounds, epoxy compounds, ultraviolet stabilizers, antistatic agents, surfactants, hydrotalcite compounds, polyol compounds, and esters thereof, and organic phosphorus Zinc glycine is expected to be used in combination with acid salts, metal oxides, metal hydroxides, basic inorganic acid salts, perchlorates, plasticizers, pigments, lubricants, fluorescent agents, processing aids, foaming agents, and flame retardants It does not hinder the effect of thermal stability, but rather exerts the effect of combined use.

Further, a basic organic zinc compound disclosed in JP-A-63-301,248 can also be added. In this case, the thermal stability appears with a pronounced synergistic effect.

Any method of adding the above various stabilizers to the halogen-containing resin may be used as long as the function is not impaired, or may be mixed simultaneously with the adjustment of zinc glycine,
Alternatively, they may be added individually.

Further, a mixture of hydrotalcites and perchloric acid disclosed in JP-A-59-140,261, JP-A-61-81,462, and JP-A-61-83,245, or a combination of an acid-treated product is also excellent in stability. It has a synergistic effect.

The halogen-containing resin applied in the present invention, polyvinylidene chloride, polyvinyl chloride, chlorinated polyethylene, chlorinated polypropylene, chlorinated polyvinyl chloride, polyvinyl bromide, polyvinyl fluoride, brominated polyethylene, chlorinated rubber, Vinyl chloride-vinyl acetate copolymer, vinyl chloride-
Ethylene copolymer, vinyl chloride-propylene copolymer,
Vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer,
Vinyl chloride-styrene-maleic anhydride terpolymer,
Vinyl chloride-styrene-acrylonitrile terpolymer, vinyl chloride-butadiene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-
Polyvinyl halides such as acrylic ester copolymers, vinyl chloride-maleic acid ester copolymers, vinyl chloride-methacrylic acid copolymers, or polymers obtained by halogenating polyolefins, copolymers of halogenated resins Polymers, and halogen-containing resins such as ABS resin and MBS
Polymer blend with resin, EVA resin, butadiene, urethane vinyl acetate, etc.

In applying the present invention, the blending ratio of the halogen-containing resin and zinc glycine is usually in a preferable range of 0.1 to 10 parts by weight based on 100 parts by weight of the halogen-containing resin. The lower limit of this range is determined by the limit at which the substantial stabilizing effect appears. The upper limit is determined from the viewpoint of economy, and both limits are estimated from experimental values.

Examples Hereinafter, the present invention will be described specifically with reference to examples. However, the present invention is not limited by these.

Example 1 Polyvinyl chloride (average molecular weight: 1050) 100 parts by weight Zinc stearate 1.6 Calcium stearate 0.4 Zinc glycine A, B, C or D 1.5 (see the following table) , Using an 8 inch roll and kneading at 190 ° C. for 4 minutes,
A sheet having a thickness of 0.5 mm was prepared. Each sheet was shredded, heated to 180 ° C. in a gear aging tester, and the time required for discoloration to a level unusable for use was measured. The results were as shown in the following table.

In addition, glycine zinc A, B and C were obtained by using a rotary speed mill for particles passing through sieves of 0.08, 0.5 and 1.0 mm, respectively.
~ 3 times crushed, D is not crushed. The details are as shown in the table below.

According to the above test results, even if the average particle size is 10 μm or less
It can be seen that heat resistance is poor when a large amount of particles of 10 μm or more is contained. Also, from the above table, the ground glycine zincs B and C obtained by the usual grinding method (one-time grinding) have particles having an average particle size of at least 10 μm even if they are considerably smaller than 10 μm. There is, but it turns out that it includes.

Embodiment 2 First, matters common to this embodiment will be described.

Compounding ratio of halogen-containing resin composition Polyvinyl chloride (Zeon 103EP) 100 parts by weight DOP 40 Zinc stearate 0.5 Calcium stearate 0.2 BHT 0.05 Dehydroacetic acid 0.05 DHOP 0.1 Basic zinc acetate 0.1 Glycine zinc Indicate in the table (base here) (Soluble zinc acetate is a reaction product of 1 mol of zinc oxide and 1 mol of acetic acid.) In carrying out the above blending, the mixture was mixed for about 1 minute with a rotary mixer, and kneaded with a 6-inch roll at 175 ° C. for 4 minutes. Then, it is processed into a sheet having a thickness of 0.5 to 0.7 m / m. Each sheet is heated to 185 ° C. in a gear aging tester and the time required for discoloration to withstand use is measured.

Preparation of zinc glycine 300 g (4 mol) of glycine and 162.8 g (2 mol) of zinc oxide
Into a desktop universal mixer, mix for about 5 minutes,
Water 612 (34 mol) was added and mixing continued for about 1 hour. After that, drying is performed at 110 ° C. to obtain zinc glycine crystals.

Measurement of Particle Size After mechanically grinding the glycine zinc crystal, the sample is observed with a scanning electron microscope. When the maximum particle size of the particles that appear in the visual field is 10 μm, the average particle size is 10 μm.
It is determined that the powder is pulverized to m or less.

When a large number of particles having a maximum particle diameter of 10 μm or more are observed, it is determined that the average particle diameter is 10 μm or more.

Fine grinding of zinc glycine The dried crystal of zinc glycine is repeatedly pulverized with a jet pulverizer, and the pulverizing operation is continued until the average particle size becomes 10 μm or less. In the case where the pulverizing operation is stopped in a state where a large number of particles having a particle diameter of 10 μm or more remain, two types are prepared.

The results of the discoloration time measured under the above assumptions are as summarized in the following table.

In the above table, Experiments 1 to 3 correspond to the case where zinc glycine is finely pulverized to 10 μm or less, and 4 to 6 correspond to the case of 10 μm or more. When the discoloration time is compared under the same blending ratio (1
-4, 2-5, 3-6) In any case, it is clear that the discoloration time becomes longer and the thermal stability is remarkably improved when the composition is 10 μm or less.

Claims (1)

(57) [Claims] (1) 100 parts by weight of a halogen-containing resin, 0.1 to 10 parts by weight of finely ground zinc glycine having an average particle size of 10 μm or less and particles having a particle size of 10 μm or less having a ratio of 70% or more. A halogen-containing resin composition containing zinc glycine having improved thermal stability.