JPS60210634A - Production of particulate polyvinyl chloride paste resin - Google Patents

Abstract

PURPOSE:To obtain a particulate polyvinyl chloride paste resin having excellent characteristics as both powder and sol, by adding a high-boiling liquid binder to a powdered polyvinyl chloride paste resin and granulating the resin under agitation at a relatively low temperature. CONSTITUTION:1-20pts.wt. liquid binder having a b.p. >=150 deg.C (e.g., dibutyl phthalate or lauryl alcohol) to 100pts.wt. powdered polyvinyl chloride paste resin. The resulting mixture is granulated with agitation at a temperature <=80 deg.C by a Henschel mixer, continuous mixer, or the like to obtain the purpose particulate polyvinyl chloride paste resin. The obtained particulate polyvinyl chloride paste resin shows excellent flow, etc., resistance to dusting and dispersibility, etc., when formed into a sol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a granular polyvinyl chloride paste resin having both excellent powder properties and sol properties.

More specifically, powdered polyvinyl chloride paste resin was added with a liquid binder by stirring granulation method, and 80%
The present invention relates to a method for producing granular polyvinyl chloride paste resin which is granulated at temperatures below .degree.

Polyvinyl chloride paste resin (hereinafter referred to as paste PVC)
) is usually used in the form of plastisol dispersed in a plasticizer or organosol in which an organic solvent is added. If coarse particles are present in plastisol or organosol, they may settle or cause problems such as streaks and scratches on the surface during coating processing. Prompt dispersion is an essential condition. For this reason,
Currently available on the market) PVO has an average particle size of 10 μm.
It comes in the form of a fine powder: As a result, many problems have arisen, such as poor powder fluidity, low bulk specific gravity, and scattering of fine powder. Poor powder fluidity causes trouble when filling or taking out packaging bags, and also hinders automated weighing.

A low bulk specific gravity requires a packaging bag with a large capacity and increases costs for storage and transportation Φ. Further, scattering of fine powder causes product loss and health and safety problems.

One way to solve these problems is to granulate PVO in the form of a fine powder.

(Pace) Fluidity which is a disadvantage of PVO 9. In order to improve powder properties such as bulk specific gravity and scattering properties through granulation, the particle size of the granulated paste PvC is increased to increase the cohesive force between the particles and to reduce the density of the granulated paste PvC so that it is difficult to disintegrate due to external force. It is desirable to use large particles. However, as the particle size increases,
Furthermore, as the cohesive force between particles increases, the dispersibility when mixed with a plasticizer decreases, making it difficult to satisfy the sol physical properties required for paste processing. As described above, the powder properties required for powder handling and the sol physical properties required for paste processing are contradictory properties, and it is extremely difficult to produce paste PVC that has both properties.

Today, granulation of fine powders to improve powder properties is performed on many powders. However, the powders currently being granulated are used for pharmaceuticals, agricultural chemicals, and detergents.

These are used in catalysts and the like either dissolved in water or as they are, and there are almost no known examples of them being used after being reconstituted into fine powder. Regarding the granulation of paste PVC, it is necessary to quickly disperse the obtained granules into fine particles when mixed with a bald plasticizer, and conventional granulation methods cannot be applied as is.

As the granulation method, transfer granulation method, compression granulation method, fluidized bed granulation method, extrusion granulation method, etc. are known.

The present inventors have also conducted research on these methods, but have not been able to find a granulation method that fully satisfies both powder characteristics and sol physical properties. Further, although granulation is possible with either method, it is difficult to supply or to homogenize the system due to the poor fluidity of paste PVC, and operation is not easy. These results also show that it is extremely difficult to produce a granular paste (PVC) that has contradictory properties of powder properties and sol properties.

The present inventors have combined excellent powder properties and sol physical properties.

As a result of intensive studies on the manufacturing method of granular paste PVC, the present inventors discovered that the objective could be achieved by adding a liquid binder to powdered paste PVCf using the stirring granulation method and granulating it at 80°C or less, resulting in the present invention. .

The present invention will be explained in detail below.

The powdered paste used in the present invention) PVO is emulsion polymerized,
Alternatively, it may be produced by micro suspension polymerization or any other polymerization method used for producing paste PVC, and may be a vinyl chloride homopolymer or a copolymer containing vinyl chloride as a main component with vinyl acetate or the like. But that's fine. (Powdered paste) PVO has an average particle diameter of usually 10 μm or less, and forms a paste when mixed with a plasticizer.

Granulation is performed by stirring granulation method. The apparatus used is a container equipped with stirring blades, and may be either a patch type stirring granulator such as a Henschel mixer or a continuous stirring granulator such as a continuous mixer. pace) PV
(No. 3 is easy to cause adhesion to walls, so it is desirable to use a scraping blade or a hummer to prevent adhesion and ensure uniform mixing.)

The purpose can be achieved if granulation is carried out at a temperature of 80°C or less, but as the size of the equipment increases, heat generation increases, and it is also desirable to be able to control the temperature during granulation in order to maintain constant quality. .

The binder used in the present invention has a boiling point of 1
It is liquid at 50°C or higher. Although granulation effects can be seen with low-boiling point solvents such as water and lower alcohols, drying must be performed, which complicates the process, and the sol properties tend to deteriorate due to the heat during drying. Moreover, the powder after drying has low cohesive force and is easily broken. PVO processing is usually carried out at temperatures above 150°C, and the boiling point is 150″C.
If the following binders remain in the granulated granular paste Pvc, foaming will occur during processing, making it impossible to obtain a good molded product. The binder needs to be liquid at temperatures up to 80°C. The binder can exhibit its effects in liquid form, and can also be easily supplied to the granulator. Specific examples of liquid binders with a boiling point of 150°C or higher include diptyl heptalate;
Dioctyl phthalate, butylbenzyl phthalate, dioctyl adipate, dioctyl sebacate, tricresyl phosphate, polyester adipate, trimellitic acid ester, plasticizers for polyvinyl chloride such as epoxidized soybean oil, decyl alcohol, lauryl alcohol Examples include higher alcohols such as, liquid paraffin, chlorinated paraffin, and nonionic surfactants. These binders are used in an amount of 1 to 10 parts by weight of paste PVC.
It can be used alone in an amount of 20 parts by weight or in a mixture of two or more.

If the amount of binder is less than 1 part by weight per 100 parts by weight of paste) P'VC, granulation will be difficult to proceed and a granular paste PVC with sufficient powder properties will not be obtained;
If the amount is more than 20 parts by weight, the sol properties will deteriorate and reproducibility will be difficult to obtain.

Since the liquid binder is contained in the granular paste (PVO) as it is, it is undesirable to use a binder that adversely affects the physical properties of the sol and the molded product.

If the solid binder has a boiling point of 150° C. or higher and dissolves in the liquid binder, it can be used in combination with the liquid binder, but even in that case, the use of the liquid binder is essential. There is no particular restriction on the method of adding the binder, and any method such as injection using a pump with equal pressure or supply by spraying from a nozzle may be used.

The temperature at which granulation is performed is 80°C or less. When granulating at a temperature higher than 80°C, the granular paste p after granulation
When va is mixed with a plasticizer and made into a sol, the viscosity increases. Further, granulation can be carried out at low temperatures, but from the viewpoint of operation and cost, it is carried out at a temperature of 0° C. or higher, preferably room temperature or higher.

By carrying out granulation using the method of the present invention, it is possible to produce a granular paste (PVO) that fully satisfies both powder properties and sol properties, but it is also possible to classify it to further improve powder properties. .

Further, during granulation, known additives used in the processing of paste PvC, such as an inorganic filler, a blowing agent, a stabilizer, a blending resin, and a thinner, can be mixed as necessary.

In this way, the method for producing granular paste (PVO) of the present invention makes it possible to improve the disadvantages of PVO (base) such as fluidity, bulk specific gravity, scatterability, etc., and as a result, rationalizes work, improves safety and hygiene, and reduces costs. It is extremely useful in terms of (7) such as down, and its contribution to industry is extremely large.

The present invention will be specifically explained below with reference to Examples, but the present invention is not limited in any way.

Examples 1-3. Comparative Examples 1 to 2 300 g of powdered paste PVC (Eilon Pace manufactured by Toyo Soda Kogyo Corporation) R-720, degree of polymerization: 850) was placed in a planetary mixer equipped with stirring blades and scraping blades with a capacity of 4 t.
was charged, and stirring was started at a temperature of 20° C. and a stirring speed of 140 rpm. Next, as a binder, dioctyl heptatalate (DOP) was added in the amount shown in Table 1 by pouring it into a container with a scale over a period of 2 minutes.
Granulation was carried out by continuing stirring for minutes.

Table 1 shows the powder properties and sol properties of the obtained granular paste (PvO).

Table 1 *1 Ratio of recovered granular paste (PVO) to the total amount of powdered paste PvC and DOP 2 Granular paste PVC was classified using a sieve, and the weight fraction was determined from the graph of the particle diameter and weight fraction. Particle size umbrella 3 (granular paste) with a ratio of 50j) DOP5 for 100 parts by weight of PVO
0 parts by weight was added and mixed for 90 seconds using a high speed stirrer to form a sol.

*4 Depth is D~! The diameter of the particles in the sol measured using a grindmeter with uniform Taber grooves up to 100μ When water (boiling point 100°C) is used as a binder, granulation is slow and the powder properties are not improved.

Further, no good molded product could be obtained by heat molding.

Example 8~? , Comparative Example 3 Granulation was carried out in the same manner as in Example 2 except that the temperature of granulation was changed.

The results are shown in Table 3.

Table 3 It can be seen from Table 3 that the base) P'VC granulated by the stirring granulation method at a temperature of 80° C. or less exhibits excellent powder properties and sol physical properties.

These granular base) PVO had good moldability and physical properties of molded products.

Examples 10-11 R-720 KawaneK as powdered paste PI'VC
Granulation was carried out in the same manner as in Example 2 using R-770 and R-761.

The results are shown in Table 4.

Table 4 *1 Polymerization degree 1650 (manufactured by Toyo Soda Kogyo ■) *2 Polymerization degree 2100 (manufactured by Toyo Soda Kogyo ■) From Table 4, powder base) PV (! is granulated by stirring granulation method regardless of type) Granular paste with excellent powder properties and sol properties) PVC
It can be seen that it can be manufactured.

Patent applicant: Toyo Soda Kogyo Co., Ltd.

Claims (1)

[Claims] Powdered polyvinyl chloride paste resin is stirred and granulated to add a liquid binder with a boiling point of 150°C or higher to 1 to 2 parts by weight per 100 parts by weight of powdered polyvinyl chloride paste resin.
A method for producing a granular polyvinyl chloride paste resist, characterized by adding 0 parts by weight and granulating at 80°C or less.