JPH0356551A - Stabilizer for pvc - Google Patents

Abstract

PURPOSE:To obtain a stabilizer for PVC providing PVC with stability, having no toxicity, consisting essentially of a basic calcium carbonate shown by specific composition formula. CONSTITUTION:A stabilizer consisting essentially of a basic calcium carbonate shown by the formula (x =0.25-2.30; n is 0.25-6). 100 pst. wt. PVC is blended with 0.1-10 pts. wt., preferably 0.5-5 pst. wt. of the stabilizer. Effects can be expected by using the basic calcium carbonate alone and can be more increased by using both the basic calcium carbonate and an existing stabilizer.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel stabilizer for PVC (polyvinyl chloride resin). Specifically, it relates to a PvC stabilizer added to hard or soft PvC. PVC is one of the most widely used resins for building materials, packaging, TA coatings, agricultural films, etc. However, energy such as heat and light causes dehydrochlorination and deterioration.
It has the disadvantage of being colored, and many stabilizers have been developed and used to overcome this disadvantage.

Typical stabilizers include lead-based, cadmium-based, tin-based,
There are Ba-Zn type stabilizers, Ca-Zn type stabilizers, epoxides, etc., and in many cases, several types of stabilizers are used in combination. Among these stabilizers that Ming is trying to develop, lead-based, cadmium-based, and tin-based stabilizers, which are used in relatively large amounts, are all associated with concerns about toxicity, although there are some differences, and there are concerns about environmental pollution and effects on the human body. This is not necessarily desirable from the standpoint of stability measures. On the other hand, B
Although a-Zn type, Ca-Zn type, and epoxide have little concern about toxicity, they cannot be said to have sufficient stability.

For this reason, especially in PvC in recent years. Efforts are being made to improve stability through low-toxicity and non-toxic formulations, and there is a strong need for non-toxic stabilizers with high stabilizing effects. The present invention was made in view of these circumstances, and its purpose is to provide a PvC stabilizer that is non-toxic, has a high stabilizing effect, and can withstand use in various environments.

In order to achieve the above object, the present invention provides a PvC stabilizer mainly composed of basic calcium carbonate represented by the following formula. c a,, (CO3)(O
H)z, −n HiO(x=0.25~2.30
, n=0.25-6.00) As is clear from the above compositional formula, in addition to the metal ion Ca, carbonate groups, hydroxyl groups,
It is water and does not contain any toxic ingredients. In addition, its shape has an average particle size of 0.3 to 1.0 μm and an aspect ratio of 5.
It exhibits some plate-like crystals. And most importantly,
As a result of intensive research into the properties of this substance, we discovered that it has the property of stabilizing pvc resin, which is difficult to predict from the conventional use of calcium carbonate powder as a filler and extender. It is. This property is thought to be due to the fact that basic calcium carbonate has the ability to trap free chloride ions in its crystal structure. The content of this substance is 0.1 to 100 parts by weight of PVC.
By adding 10 parts by weight, usually 0.5 to 5 parts by weight, it is effective as a stabilizer for PvC, regardless of whether it is hard or soft. In this case, although an effect can be expected even when used alone, the stability of PvC can be further enhanced when used in combination with an existing stabilizer.

For 100 parts by weight of PVC, 5 parts by weight of dioctyl phthalate as a plasticizer, 1 part by weight of calcium stearate as a lubricant, and 5 parts by weight of basic calcium carbonate as a stabilizer.
After taking the weight part into a beaker and stirring well with a glass rod,
The mixture was put into a mixing roll kept at 165°C and kneaded. The kneaded sheet with a thickness of approximately 1 mm was cut into 3 mm squares, placed in a gear oven at 190° C., and discoloration due to heating deterioration was observed at regular intervals. As a result, it turned yellowish brown in 20 minutes and turned black in 230 minutes. The blending ratio was the same as in Example 1, but no basic calcium carbonate was added. The conditions for the deterioration test were exactly the same as in Example 1. As a result, it turned pale brown after 10 minutes, and turned black after 90 minutes. 5 parts by weight of dioctyl phthalate as a plasticizer, 1 part by weight of calcium stearate as a lubricant, and 3 parts by weight of epoxidized soybean oil as a stabilizer, per 100 parts by weight of the main PVC. 2.5 parts by weight of Ca-Zn stabilizer and 3 parts by weight of basic calcium carbonate were placed in a beaker, formed into a sheet in the same manner as in Example 1, and placed in a gear oven at 190°C.
Discoloration due to heat deterioration was observed at regular intervals. As a result, it began to turn slightly yellow in 20 minutes, and turned black in 360 minutes. The blending ratio was the same as in Example 1, except that basic calcium carbonate was not added. The deterioration test conditions were exactly the same as in Example 2. As a result, it turned pale yellow in 20 minutes and turned black in 150 minutes. 50 parts by weight of dioctyl phthalate as a plasticizer, 0.2 parts by weight of zinc stearate as a lubricant, and 1 part by weight of basic calcium carbonate as a stabilizer, per 100 parts by weight of PVC.
．． 8 parts by weight was placed in a beaker and stirred thoroughly with a glass spoon to make it homogeneous. This was put into a mixing roll kept at about 150°C and kneaded to form a sheet, then pressed into a flat plate with a thickness of IIm, which was then heated and deteriorated in an oven at 180°C and observed for discoloration at regular intervals. As a result, 3
The color changed to yellowish brown at 0 minutes, and changed to brownish black at 240 minutes. In addition to the Ura-Koyu Example 3, 0 dibenzoylmethane was added as a lubricant.
．． 3 parts by weight was added, and the other conditions were the same as in Example 3.
The results were almost the same as in Example 3; the color changed to light brown in 30 minutes and changed to brownish black in 240 minutes. The blending ratio was the same as in Example 4, but no basic calcium carbonate was added. The deterioration test conditions were exactly the same as in Examples 3 and 4. As a result, it turned dark brown in 15 minutes, and after 30 minutes it turned dark brown.
It turned black in minutes. For 100 parts by weight of PVC, 5 parts by weight of dioctyl phthalate as a plasticizer, 1 part by weight of calcium stearate as a lubricant, and 5 parts by weight of basic calcium carbonate as a stabilizer.
The weight part was taken into a beaker and stirred well with a glass rod. This was put into a mixing roll kept at 165°C and kneaded, and then pressed into a flat plate with a thickness of 1 inch. This sheet was cut into 3x1 square pieces, placed in a gas oven at 190°C, and observed for discoloration due to heat deterioration at regular intervals. As a result, it started to turn slightly yellow after 20 minutes, and 17
It turned almost black in 0 minutes. Table 1 shows the above examples and comparative examples. According to the present invention, the stability of PvC resin can be improved with non-toxic formulation or with lower toxicity than before. That is,
The present invention is of great practical importance in terms of resource saving measures such as safety measures against environmental pollution and effects on the human body, and long-term effective use of PVC by increasing its durability.

Claims (1)

[Claims] 1. A stabilizer for PCV mainly consisting of basic carbon calcium represented by the following compositional formula. Ca_1_+_x(CO_3)(OH)_2_x・nH
_2O [x=0.25-2.30, n:0.25-6.
00]