JPS6015433A - Production of jelly-like pvc composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition excellent in elasticity, etc., and suitable as a cushioning material or the like, by dissolving waste PVC articles in a solvent, removing insolubles, uniformly mixing a relatively large amount of a liquid plasticizer, and removing the solvent. CONSTITUTION:100pts.wt. waste polyvinyl chloride article is dissolved in a solvent (e.g., tetrahydrofuran) and the insolubles are removed to prepare a uniform PVC solution. This solution is uniformly mixed with 150-1,200pts.wt. normally liquid plasticizer (e.g., dibutyl phthalate) and, optionally, other additives (e.g., stabilizers or colorants). The purpose jelly-like PVC composition is obtained by removing the solvent form the resulting solution to separate a uniform composition containing PVC and the plasticizer. It is also possible to impart flame retardancy to the product by using a flame-retarding plasticizer such as tricresyl phosphate.

Description

[Detailed description of the invention] The present invention relates to a method for producing a jelly-like PVC composition.

PVC (polyvinyl chloride) is one of the typical synthetic polymers, and a variety of products such as various molded bodies, films, and foams are manufactured as a thermoplastic resin. However, not all the possibilities of PVC have been revealed. For example, whether jelly formation, which has already been widely applied to natural polymers such as agar, gelatin, and pectin, is also possible for PvC, and if so, what physical properties would PvC jelly have? Nothing is known about it.

If pvc forms a jelly, we get pv
C-jelly is expected to exhibit physical properties that are completely different from conventional PVC products, and is expected to open up new uses for PVC.

In view of the above circumstances, the inventors conducted various studies on the formation of PVC jelly, and found that PVC exhibits uniform elasticity.
Having successfully obtained a VC composition, we hereby disclose a method for its production.

That is, the present invention provides product waste 1 of polyvinyl chloride.
A process of dissolving the 00 critical part in a solvent and further removing insoluble matter to prepare a uniform polyvinyl chloride solution, and adding 150 to 1200 parts by weight of a plasticizer that is liquid at room temperature and other materials as necessary to the solution. A jelly comprising the steps of adding and uniformly mixing a compounding agent, and removing the solvent from the mixed solution to separate a composition uniformly containing the polyvinyl chloride and the plasticizer. Mr. P
This is a method for producing a VC composition.

The PVC product waste used as a raw material in the present invention may be of any kind, such as molded product waste, film waste, foam product waste, or defective product waste from factories. That is, since these are once dissolved in a solvent and used in a solution state, there is no problem with any product as long as it can be dissolved in the solvent. Therefore, the present invention has great significance as a method for recycling these PVC wastes.

The solvent used in the present invention must be capable of dissolving the PVC waste and be compatible with the plasticizer added later. Furthermore, from the viewpoint of workability, it is desirable that the material has sufficient ability to dissolve PVC at room temperature. The most common such solvents are highly polar organic solvents, especially tetrahydrofuran (THF).
is the most suitable.

Examples of plasticizers that are liquid at room temperature in the present invention include dioctyl phthalate (DOP) and dibutyl phthalate (DOP).
BP), heptatarate plasticizers such as dioctyl phthalate (DIDP), phosphoric acid ester plasticizers such as trioctyl phosphate (TOP), fatty acid ester plasticizers such as zooctyl adipate (DOA), methacrylic Acid ester-based plasticizers and other plasticizers that are liquid at room temperature and have been conventionally used for molding PvC can be used.

Sir, this and tricresyl phosphate ('rcp
) and other flame-retardant plasticizers can be added to make the product flame-retardant.

By the way, in the production of conventional PvC products, the above-mentioned plasticizers have been used simply to provide necessary fluidity during molding and to provide impact resistance and flexibility to the products. Therefore, the amount used was 30 parts by weight or less in the case of hard products, and about 40 to 100 parts by weight even in the case of soft products, taking into account deterioration of physical properties and bleeding. In contrast, in the present invention, the above-mentioned plasticizers are used rather as solvents for the formation of PVC jelly. Therefore, the amount used is 150 to 1200 parts by weight, which is extremely large compared to the conventional amount.

Since the present invention uses the PVC waste as a raw material, the raw material contains various impurities such as sand, which remain as insoluble matter when dissolved in the solvent. Therefore,
After preparing a PVC solution by dissolving raw material PVC waste, it is necessary to remove the above-mentioned insoluble matter by filtration, decantation, or the like. The plasticizer is added to the homogeneous PVC solution from which insoluble matters have been removed, and the mixture is stirred and mixed to form a homogeneous mixed solution. At that time, various additives such as stabilizers such as zinc stearate, colorants such as dyes and pigments, or fillers may be mixed together with the plasticizer, if necessary.

After preparing a uniform mixed solution containing PVC and the plasticizer, the solvent is removed by the method described below to separate a jelly-like PvC composition uniformly containing the plasticizer. This is presumed to be due to the fact that as the solvent was removed, the molecules of PvC encapsulated the plasticizer and formed a mesh-like keel, thereby forming a jelly of PvC with the plasticizer as a dispersion medium. be done.

Note that the solvent is removed from the mixed solution by the following method. That is, the mixed solution is directly heated to evaporate only the solvent, and the solvent is removed by a so-called dry-up method. When the solvent is removed, a jelly-like PVC composition uniformly containing the plasticizer remains separated. This method cannot be applied unless the boiling point of the solvent is lower than the boiling point of the plasticizer. Therefore, it is suitable when using a volatile solvent with a low boiling point.

The jelly-like PvC composition separated as described above can also be subjected to molding.

The PVC composition made according to the present invention has a jelly-like elasticity and feel similar to agar jelly.

This occurs when the PVC and plasticizer solutions are separated.
The c molecule takes up the plasticizer and becomes dull, which makes P
It can be inferred that vC jelly was formed. However, this jelly-like PVC composition does not cause syneresis like agar jelly and is extremely stable.

It also has considerable elongation properties and tensile strength, and does not tear easily like agar rolls. Furthermore,
It has the characteristics of being highly deformable and having excellent shape following properties.

Furthermore, the product of the present invention shows no deterioration in physical properties or increase in hardness at low temperatures, and exhibits the same behavior as at room temperature even when used for a long time at -30°C to -40°C.

As mentioned above, the jelly-like PVC obtained by the present invention
The composition is a completely new composition with characteristics not found in conventional soft PvC, and by taking advantage of its characteristics, it can be used for various purposes such as the following.

First, it can be used as a cushion material by taking advantage of its elasticity. Urethane foam is currently widely used as a cushion material, but it has been pointed out that the elasticity of urethane foam has a large hysteresis loss, causing a feeling of bottoming out. In contrast, the elasticity of the jelly-like PvC composition obtained in the present invention is characterized by extremely low hysteresis loss. Therefore, if this is used in place of a water bed used for patients, for example, it is extremely effective in preventing bedsores since it has excellent shape-following properties.

In addition, it can be used as various sealing materials or toys by taking advantage of its excellent shape-following properties.

Example 1 100 parts by weight of used agricultural PVC film was dissolved in tetrahydroflough (THF) at room temperature to give a concentration of 10%.
A solution of This was mixed with 400 parts by weight of VOP (dioctyl phthalate) to form a homogeneous solution, which was subjected to solvent removal and drying to obtain a jelly-like PVC sheet.

Of course, the solvent THF used for this purpose was recovered and reused, and the recovery rate was 90%.
I was shocked.

Example 2 A PVC sheet with uniform jelly was obtained in the same manner as in Example 1 except that 600 parts by weight of DIDP was used as a plasticizer.

Note that the recovery rate of TFtF was 90%.

Example 3 400 parts by weight of DIDP and 20 parts by weight of DOA as plasticizers
Using a 0-fold corner part, the same procedure as in Example 1 was carried out to obtain a uniform jelly p.
Get a VC sheet. The recovery rate of THF was 90%.

Example 4 A PVC sheet with uniform jelly was obtained in the same manner as in Example 1 except that 1000 parts by weight of DOP was used as a plasticizer. The recovery rate of THF was 90%.

Example 5 A jelly-like PVC sheet was obtained in the same manner as in Example 1 using 600 parts by weight of TOP as a plasticizer.

The recovery rate of TI(F) was 90%.

Example 6 When the same procedure as in Example was carried out using TCP 700 heavy dark part as a plasticizer, a jelly-like PvC sheet was obtained with a THF recovery rate of 90%.

Claims (1)

[Claims] 100 parts by weight of vinyl chloride product waste is dissolved in a solvent, and insoluble matter is further removed to obtain a homogeneous 71? A step of preparing a ribinyl chloride solution, a step of adding and uniformly mixing 150 to 1200 parts by weight of a plasticizer that is liquid at room temperature and other compounding agents as necessary to the solution, and a step of adding and uniformly mixing the plasticizer that is liquid at room temperature to the solution, and A method for producing a jelly-like PvC composition, comprising separating a composition uniformly containing the polyvinyl chloride and the plasticizer by removing the solvent.