JPS58194907A - Production of vinyl chloride paste resin - Google Patents

Abstract

PURPOSE:To facilitate separation of free water from solids to thereby produce the titled paste resin in good efficiency, by adding a specified water-soluble cationic high-molecular compound to a vinyl chloride (co)polymer latex and coagulating the particles in the latex. CONSTITUTION:Use is made of a water-soluble cationic high-molecular compound of formula I or II [wherein R1-R4 are each H or a 1-4C alkyl, Z is -(CH2)-, formula III, m and n are each 1-6, X and Y are each a halogen and n>=2], preferably, one having positive charges (surface charge density >= about 10<-5>C/cm<2>) and a particle diameter of about 0.01-10mu. Namely, about 0.001- 5wt%, based on the weight of the contained particles, above high-molecular compound is added to a vinyl (co)polymer latex to coagulate the particles without flocculating them, the free water is removed by decantation, filter pressing or a like operation, and the obtained cake (solids concentration about 65-78%) is dried.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a vinyl chloride paste resin (hereinafter referred to as base paste) that separates vinyl chloride resin after increasing the solid content concentration by adding a water-soluble cationic polymer flocculant to vinyl chloride resin latex. (referred to as resin).

In recent years, in the production of base resin, with the rise in the price of crude oil, various methods have been considered to remove water from latex to increase the solid content concentration to prevent increases in energy costs during drying.

Conventionally, paste resin has been produced using emulsion polymerization or microsuspension polymerization to produce latex with an average particle size of about 3 μm or less. The method of spray drying latex has been widely used due to its quality. However, according to this method f, the cost increases unless the solid content concentration in the latex is made as high as possible.

In addition, as a stable latex, if the solid content concentration is not maintained at 5% or less, a large number of aggregates will easily occur during polymerization, or many quality problems will occur such as the need for large amounts of auxiliary agents such as emulsifiers. There are other problems. Therefore, the conventional method has been to concentrate the particle concentration in latex to about 30 to 40% and then dry it by spray drying or the like. On the other hand, it is easy to imagine that after agglomerating the latex, it can be subjected to p-filtration or centrifugal dehydration to increase the particle concentration and thereby reduce the drying energy cost by one degree. However, if the latex is simply agglomerated, a large amount of water will be included in the agglomerate, making it impossible to carry out filtration or centrifugal dehydration.
However, it is not preferable because it has strong adhesive properties and no fluidity, making it extremely difficult to handle industrially.

In addition, for paste resin, it is necessary to remove the moisture in the latex and then disperse polyvinyl chloride in a plasticizer to give plastisol, but it is not possible to simply agglomerate it with polyvalent metals or conventionally known flocculants. Otherwise, the plastisol will not turn into plastisol, or the viscosity of the plastisol will become extremely high, greatly impairing its commercial value as a paste resin. That is, conventional aggregation methods have been based on methods such as deactivating the effect of the emulsifier in latex, linking particles with polymer chains9, or removing particle surface charges. 111. :1. In the agglomeration method - once the dust particles are dried, the particles do not redisperse in the plasticizer. The well-known theory of agglomeration is Snnoln.
As stated in Chowski's theory of rapid agglomeration, while each latex particle is undergoing Brownian motion, the particles collide with each other and agglomeration occurs, which reduces the total number of particles. , the aggregation is completed and finally becomes one large lump.

In such agglomeration, water is included in the aggregates, and even after dehydration, the water content remains high. Furthermore, since the particles adhere to each other, they are difficult to disperse even if they are attempted to be dispersed after dehydration and drying. Therefore, this method is inappropriate as a method for producing paste resin.

The present inventor previously proposed a method for aggregating latte and tuxu by adding a water-soluble cationic polymer compound to latex in a patent application filed in 1972-/
, 05g,..., filed as No. 7, but subsequent research revealed that even a water-soluble cationic polymer compound with a structural formula not described in the earlier application had a good flocculating effect on vinyl chloride resin latex. I found it.

As a result of exploring the phenomenon of aggregation occurring without adhesion of particles in latex, the present inventor found that when a specific water-soluble cationic polymer compound is added to latex, particles can be agglomerated without adhesion. Possible and water ・
The present invention was achieved by discovering that it is easy to separate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a paste resin in which particles in latex are aggregated without coagulating and the solid content is separated from free water.

Therefore, the gist of the present invention is to separate the solid content after adding a water-soluble cationic polymer compound represented by the following general formula C1:l or (It) to vinyl chloride resin latex or vinyl chloride copolymer latex. A method for producing a vinyl chloride paste resin is provided.

General formula CI] General formula [11] (wherein, R,, R2, R, and R2 are hydrogen atoms or alkyl groups with carbon atoms 1 and g, Z is -(CH2)m- group, -CH2→Q ←CH2- group,
-(CH2)m-〇-(CH2)n- group, X and Y are halogen atoms, which may be the same or different.

m and n are integers from t to B, and may be the same or different.

t is an integer greater than or equal to 2 1 are shown respectively. ) Detailed explanation of T4 shots! i name.

Vinyl chloride resin latex or vinyl chloride copolymer latex (hereinafter sometimes simply referred to as latex) is produced by emulsion polymerization (copolymerization) or microsuspension polymerization (copolymerization) of comonomers that can be copolymerized with it. ) can be obtained. Specific examples include polyvinyl chloride latex (emulsion), vinyl chloride-vinyl acetate copolymer latex, and the like.

The water-soluble cationic polymer compounds of general formulas [I] and [■] used in the method of the present invention are produced by various synthetic methods.

Compounds represented by the general formulas [1) and [11] have a structure in which the alkyl groups R1s, R2'', R3, and a hydrogen atom or an alkyl group of 01 to 0, i.e., a methyl group, an ethyl group, a propyl group, Preferably, methyl group is particularly preferred.

X and Y are chlorine, ru or bromine atoms, and both are IQ-4
'Ah 7. Yo:1・:・1. 2. -t, carbon man-hours 7
~.

The m group of Pa1, specifically a methylene group, an ethylene group, or a propylene group, is preferable. The value of t may be any integer greater than or equal to 2, but it is preferably in the range of /0-, /A;0, preferably in the range of SO to 100. The larger the value of t, the greater the aggregation effect. The numbers m and n become larger. Therefore, the value of m+n and the number of t should be appropriately selected in consideration of the charge of the latex particles used.

The compound represented by the general formula [■] has RB in the structural formula
It is preferred that s R4 is a hydrogen atom.

The surface charge density of these compounds is 10 microcoulombs/c1f! Particle diameter θ having a positive charge equal to or greater than o
Particles of iμm-1oμm are desirable.

The water-soluble cationic polymer compound (hereinafter referred to as flocculant) is
The negatively charged latex particles in the latex collide with the positive charges in the flocculant, causing the latex particles to aggregate, but the aggregated particles repel each other, resulting in good dispersibility, and the latex as a whole The resulting dispersion has excellent fluidity and good water separation properties without becoming tofu-like.

The flocculant may be used after being dissolved in water or other medium, if necessary.

Therefore, the amount of the flocculant added is 0.00000000000000000000000 though is 0.0000000000,000 per the weight of the particles in the latex. By adding θθ/−5% by weight, preferably in the range of 0°0l−2% by weight, various agglomerated particles can be obtained. As the amount of latex added is increased little by little, the viscosity of the latex gradually increases, and as the amount is further added, the viscosity becomes 9. Yu. When the process is observed using an optical microscope, the latex particles initially interact with each other as iodine polymers and aggregate, and exist as large aggregated particles. When the amount added is small, the aggregates with a small particle size are the main body, and as the amount added increases, the aggregate particle size increases by 4μ, and when further addition is made, the aggregate particle size becomes divided. The agglomerated particle size changes to a substantially uniform diameter of about 10 to 100μ, especially about 20 to Sθμ. The diameter of the aggregated particles can be adjusted to a desired size by adjusting the amount of the flocculant added.

According to the method of the present invention, a flocculant is added to the latex,
If left after stirring, the water and latex particle aggregates will easily separate, and the water can be removed by decantation.
Dehydration using a centrifugal separator can reduce the solid content to about 72%, and using a filter press can reduce the solid content to about 7%.

Therefore, according to the method of the present invention, it is only necessary to evaporate about 2λ to 35% of water, so the energy cost associated with conventional drying is significantly reduced, making it possible to significantly reduce manufacturing costs.

Furthermore, the dehydrated cake obtained according to the present invention rapidly loses its fluidity when the moisture content falls below a certain value. Until then, it exhibits clay-like flow properties despite relatively high particle concentrations. Dehydrated cakes can also be granulated by utilizing these properties. Granulated Pace 1 Niresin has a small bulk density and generates a lot of powder, which tends to cause hygiene problems when handling, but because it is in a granular form, it produces less powder. , not only can you reduce the cost of maintenance equipment for the working environment, but also
The bulk density is about 0.sg/ml, which is about λ times that of conventional base resin, and has the advantage that transportation costs and warehouse storage costs are about half of conventional ones. Furthermore, since the granulated base resin can be transported by pneumatic transportation or the like, bulk transportation and further automatic measurement is possible in this case. Therefore,
Compared to conventional handling of powder, it is possible to streamline the work and improve the work environment.

The method of the present invention will be explained in detail in Examples below.
The present invention is not limited to the following examples unless it exceeds the gist thereof.

In addition, "parts" in the examples represent "parts by weight."

'#''fJ / ,,: Using a 300 t pressure vessel, add 0.xl of sodium lauryl sulfate, 0.03 part of potassium persulfate, 7 parts of sodium bicarbonate, and 0.07 part of sodium sulfite to salt. It was added to 100 parts of vinyl chloride monomer and emulsion polymerized at 40° C. until the saturated vapor pressure of the vinyl chloride monomer was reduced to 2′ by 9/α to obtain a vinyl chloride resin latex with an average particle size of θ0 g μm.

The particle solids content in this latex was 3g%.

Separately, 3 was added dropwise to the mixed solvent itO in a nitrogen stream at room temperature using a three-ring flask over 2 hours, and then 2 tons of water was added and left for t weeks. This polymer compound is a compound in the general formula [1] in which e is a butylene group and X and Y are each pro3v.

The aqueous solution thus obtained was mixed with the above-mentioned latex/
00 kg, 1. After adding θ3 and stirring slowly at 0°C, dehydration was performed using a Tomoe Kogyo HpAbo super decanter. A dehydrated cake with a moisture content of 37% is processed using a twin-screw horizontal extrusion granulator EXD-40 manufactured by Fuji Paudal Co., Ltd.
Extrusion granulation was performed using a circular mesh with a diameter of /, / mm to adjust the moisture content in the dehydrated cake to 2'A-29%. This sample was dried in a fluidized fluid dryer using hot air at SO 0 C for /, j hours to obtain a dry resin with a water content of θ, 1 or less.

The bulk density of the obtained resin was 0. ! ;1lfl/cc, which is 0.2 of normal base resin! flilcc
0.0! ; It had a very large value compared to the value of g/cc.

227,700 parts of dioctyl phthalate (・
0P) 60 parts, nonionic surfactant 0.6 part, Ca-
A plastisol was prepared by adding 3 parts of a Zn-based heat stabilizer and 3 parts of epoxidized soybean oil, and a B-type viscosity measurement and an open heat stability test were conducted, and the results are shown in Table 1. Open thermal stability test is /q! ;''(:j) After being left in a closed hot air circulation container for io minutes, the film was taken out and kept at the same temperature until it turned black.

Example 3 In a 3T autoclave, diallyldimethylammonium chloride 37 and dimethyl sulfoxide iosg
was added with ammonium sulfate/E in a nitrogen atmosphere for 30
Polymerization was carried out at ℃ for an SO hour without stirring. The obtained solid was dissolved in methanol qi and then reprecipitated with a large amount of acetone. The intrinsic viscosity was measured in a .N-Na0t solution and found to be o, qi. This compound has the general formula [■] in which R1 and R2 are methyl groups, R8 and R,
is a hydrogen atom and X is a chlorine atom.

After adding 200g of this methanol solution to 3Ot of the latex used in Example t, it was decanted using a Super Decanter pA60 manufactured by Tomoe Kogyo ■.
°"n: 1., :Ido, 7"'1 and the percentage in the dehydrated cake was 31%.

The obtained dehydrated solid content was dried at 50° C. using a shelf dryer to obtain a dry resin.

The same test as in Example 1 was conducted on the dried resin.

Comparative Example 1 3 g of aluminum sulfate was added to 7000 ml of the PvC latex used in Example 1 to cause agglomeration.

The entire product solidified and was dried in a tray type dryer with s o '' O in a state where dehydration was impossible, to obtain a dry resin.

Comparative Example 2 To 7000 ml of PVO latex used in Example 1, 2 ml of ordinary cationic flocculant (modified polyacrylamide type) was added.
When agglomerated using g, the whole became cream-like and water was not released, making it difficult to dehydrate using Okigami paper.

Comparative Example 3 The latex used in Example 1 was directly dried in a mini-spray dryer manufactured by Yamato Kagaku.The temperature of the hot air was 120°C on the inlet side and 50°C on the outlet. (Conventional method performed without any treatment) It was impossible to thermally dehydrate latex by centrifugal dehydration or offshore filtration if the latex was left as it was.

Table 1

Claims (1)

[Claims] (1) A water-soluble cationic polymeric carbonate compound represented by the following general formula [1] or [■] is added to vinyl chloride resin latex or vinyl chloride-based comonomer latex, and then the solid content is separated. A method for producing a vinyl chloride paste resin. General formula [■]. General formula [11] (In the formula, s R1, R2, R1 and R4 are hydrogen atoms or alkyl groups with the number of carbon atoms/-&, 2 is -(CH2)m- group, c R2(yc R2- group, or -(CH2)rn-〇-(CH2)n- group, X and Y are halogen atoms, which may be the same or different. m and n are integers of /-4 and may be the same They may be different. t represents an integer of 2 or more.)