JPS6354002B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a paste sol containing a plasticizer directly from an aqueous latex of vinyl chloride paste resin. Conventionally, paste sols such as plastisols and organosols have been prepared by once spray-drying and pulverizing an aqueous latex after polymerizing a vinyl chloride paste resin to produce a paste resin, and then adding a plasticizer to the resin. According to this method, the solid content concentration of the latex subjected to spray drying after vinyl chloride polymerization is usually 30
~60% by weight, requiring a large amount of water to be evaporated, and since the spray-dried resin was an aggregate, the particle size was large and required pulverization. These steps consume a large amount of energy, contributing to the high cost of paste resin. In addition, in the actual application of paste resins, these paste resins are kneaded with plasticizers, heat stabilizers, and other additives and used as paste sol such as plastisol or organosol. Because the resin is a fine powder, there is a lot of dusting,
This was a problem in handling. This dusting problem also occurs in the paste resin manufacturing process, and special equipment is required to ensure safety and health. In short, there were problems in terms of energy conservation and occupational health. As a result of extensive research into a method for producing paste sol directly from latex without going through the spray drying and pulverization steps, the present inventors found that paste sol can be produced by directly adding a plasticizer to paste resin latex after vinyl chloride polymerization. When producing latex, if a specific oil-water separating agent is added, the water in the latex will be easily separated and the paste resin will quickly transfer to the plasticizer layer, and then the plasticizer layer can be easily removed. It was discovered that a paste sol can be obtained, and the present invention was achieved. That is, an object of the present invention is to provide a method for producing a paste sol directly from latex after vinyl chloride polymerization, without going through spray drying and pulverization steps. Therefore, the gist of the present invention is to provide a method for directly producing a paste sol from a mixed system of vinyl chloride paste resin latex and a plasticizer, in which the general formula HO(C ₂ H ₄ O)a-(C _{3 H6O} )b-( _C2H4O ) _cH
...[] [In the formula, a+b+c is an integer from 20 to 110, a+c/
The ratio of b shows a value of 0.01 to 0.4. a and c may be different] or general formula [In the formula, x ₁ + y ₁ , x ₂ + y ₂ , x ₃ + y ₃ and x ₄ + y ₄ are each integers from 5 to 60, y ₁ /x ₁ , y ₂ /x ₂ , y ₃ /x ₃ ,
And the average y/x ratio of the sum of y ₄ /x ₄ shows a value of 0.01 to 0.3. x ₁ , x ₂ , x ₃ , and x ₄ and y ₁ , y ₂ , y ₃ , and y ₄ may each be the same number or different numbers. ] A method for producing a paste sol characterized by containing an oil/water separating agent represented by the following. The method of the present invention will be explained in detail. The vinyl chloride paste resin latex that can be used in the method of the present invention can be produced by adding vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith, such as vinyl acetate, acrylic acid, methyl acrylate, etc., by a conventional emulsion polymerization method or finely divided polymerization. Preferably, the latex is produced by suspension polymerization. The comonomer copolymerizable with vinyl chloride is not limited to the above-mentioned specific examples, and the type of emulsifier or suspending agent used during polymerization is not particularly limited either. In the method of the present invention, it is particularly preferable to use emulsifiers produced by emulsion polymerization, and examples of emulsifiers used include sodium dodecylbenzenesulfonate, sodium tridecylbenzenesulfonate, and sodium tetradecylbenzenesulfonate. Sodium salts of alkylbenzenesulfonates, sodium salts of sulfonates such as sodium normal paraffin sulfonate whose alkyl group has 14 to 16 carbon atoms, disodium sulfosuccinate-N
- sulfosuccinic acid alkyl ester sodium salts such as octadecylamide, dioctyl sodium sulfosuccinate, dihexyl sodium sulfosuccinate, or sulfosuccinic acid alkylamides, alkyl ester sodium salts such as sodium lauryl sulfate, sodium myristate, Fatty acid sodium or ammonium salts, such as ammonium myristate, sodium palmitate, sodium laurate, etc., are advantageous and give favorable results when using the latex disrupting agents described below. In addition, the latex may contain a polymerization aid added before or during the polymerization, powder fillers such as calcium carbonate, as long as they do not adversely affect the paste sol formation described below. The latex may contain various physical property improving aids or processing aids such as lipophilic heat stabilizers, colorants, ultraviolet absorbers, antioxidants, lubricants, and fillers. Although the solid content concentration of the latex varies depending on the bath ratio of the polymerizable monomer and water, additives, and the degree of polymerization, it is preferable to have a higher solid content in consideration of the addition of plasticizer, water separation, the size of the equipment, etc. Generally, it is desirable to use 30% by weight or more of the total latex. The plasticizer used in the method of the present invention is not particularly limited, and may be any of a variety of plasticizers that can be used as plasticizers for vinyl chloride resins. For example, phthalate plasticizers such as dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, diisodecyl phthalate, butyl lauryl phthalate, ditridecyl phthalate, butyl benzyl phthalate, butyl phthalyl butyl glycolate, trioctyl trimellitate, etc. Trimethic acid ester plasticizers, phosphate ester plasticizers such as tricresyl phosphate, trioctyl phosphate, tri-n-butyl citrate, dioctyl adipate, butyl benzyl adipate, dioctyl azelaate, dioctyl sebacate, methyl acetyl ricinoleate Examples include fatty acid ester plasticizers such as ester plasticizers, alkylepoxy stearates, and epoxy plasticizers such as epoxidized soybean oil. Among them, one kind or a mixture of two or more kinds of plasticizers can be used. The amount of plasticizer added to the latex varies depending on various conditions such as the method of separating the paste sol from the latex, the separation operation, and the final use of the paste sol, but the amount used is not particularly limited. , based on 100 parts by weight of solids in latex
It is desirable to use 20 parts by weight or more, usually up to 100 parts by weight, preferably up to 50 parts by weight. For example, if it is desired to take out the paste sol in granular form, the amount of plasticizer should be about 20 to 30 parts by weight, and if it is desired to take out the paste sol in sol form, 30 parts by weight, preferably 40 parts by weight or more may be used. If the amount of plasticizer is less than 20 parts by weight based on 100 parts by weight of solid content in the latex, it will be difficult to completely transfer the paste resin in the aqueous phase to the plasticizer phase, and the use of plasticizer will be difficult. If the amount exceeds 100 parts by weight, not only will the processing amount increase, but the resulting paste sol will not be able to be used in high-concentration fields. Therefore, it is preferable to take out a paste sol with a high concentration of up to about 50 parts by weight of plasticizer and dilute it to an appropriate concentration before use. The oil/water separation agent represented by the general formula [] to be added to the method of the present invention is a polymeric activator obtained by, for example, adding and copolymerizing ethylene oxide to a polymer obtained by addition polymerizing propylene oxide to propylene glycol. It was manufactured by a known method. In the formula, one of a or c may be O, and the total amount of a, b and c is 20 to 110
in the range of 30 to 90, and a+
Preferably, c/b is in the range from about 0.01 to 0.4, especially from 0.05 to 0.15. Propylene oxide and ethylene oxide react almost completely during the production of oil-water separation agent, so
The value of a+b+c and a+c/b defined in the present invention
The value is expressed as the molar ratio of propylene oxide and ethylene oxide added (charged) during production of the oil-water separation agent. In addition, the oil-water separating agent represented by the general formula [] is
It is produced by a known method similar to the general formula [], and for example, ethylene oxide is added to a polymer obtained by addition polymerizing ethylene diamine with propylene oxide to form a copolymer. During the ceremony,
Any of y ₁ , y ₂ , y ₃ and y ₄ may be O, and the values of y ₁ +x ₁ , y ₂ +x ₂ , y ₃ +x ₃ and y ₄ +x ₄ (hereinafter, representative and y+x) are each 5
~60, especially preferably in the range 20-40,
Average y/x of y ₁ /x ₁ , y ₂ /x ₂ , y ₃ /x ₃ and y ₄ /x ₄
The value ranges from approximately 0.01 to 0.3, preferably from 0.05 to
The value range is 0.15. The numbers of x ₁ , x ₂ , x ₃ , and x ₄ may be the same. Propylene oxide and ethylene oxide, like the oil-water separation agent of the general formula [], react almost completely during the production process of the oil-water separation agent and also undergo an addition reaction on the average. The value of /x was expressed as the molar ratio of propylene oxide and ethylene oxide used in the production of the oil-water separating agent. These oil-water separating agents are copolymerized polymers of propylene oxide, which mainly acts as a lipophilic group, and ethylene oxide, which acts as a hydrophilic group, so their molecular weight, HLB, etc. can be continuously and freely changed. It is possible to manufacture a wide range of products, and in the method of the present invention, the paste sol manufacturing conditions,
Various oil/water separating agents can be selected taking into consideration the intended use of the paste sol. However, the amount of these oil-water separating agents added is not particularly limited, but the type of oil-water separating agent,
It may vary depending on the type of plasticizer, the amount of water in the latex, the salts present in the latex, etc.
Usually, it is desirable to use 0.001 to 2 parts by weight, preferably 0.01 to 1 part by weight, particularly 0.01 to 0.1 parts by weight, per 100 parts by weight of latex. If less than 0.001 part by weight is added, rapid oil/water separation cannot be expected, and if more than 1 part by weight is added, no significant improvement in effect will be observed, which would be economically disadvantageous. The method of the present invention involves stirring a mixed system of vinyl chloride paste resin latex and a plasticizer in the presence of an oil-water separating agent represented by the general formula [] or [], so that the paste resin is transferred to the plasticizer phase. Stirring is continued until the paste sol and water are completely separated, and the upper aqueous phase and the lower paste sol phase are separated. As the oil/water separating agent, those of the general formula [] and those of the general formula [] may be used together. The timing of adding the plasticizer and the oil/water separating agent to the latex is not particularly limited, but it can be added at any time after the paste resin polymerization. However, in order to speed up the transition of the paste resin to the plasticizer phase, the dispersion system of the vinyl chloride paste resin latex is destroyed and the paste resin is gently agglomerated, and then the plasticizer and oil/water separation agent are simultaneously added. Alternatively, it is preferable to add them separately. Methods for destroying the dispersion system of vinyl chloride paste latex include, for example, applying mechanical shearing force such as high-speed stirring, irradiating with ultrasonic waves, heating with steam, etc., and using hydrochloric acid, caustic soda, etc. Various methods are employed, such as adding an acid or alkali to decompose the dispersant, adding a polymer flocculant such as polyacrylamide, and freezing with a plugging agent. Preferably, latex-destroying agents such as soft polyvalent metal salts are used. Examples of the latex destroying agent include organic acids such as formic acid, acetic acid, oxalic acid, maleic acid, adivic acid, succinic acid, aliphatic carboxylic acids, hydrochloric acid, sulfuric acid, and phosphoric acid, or inorganic acids such as barium, calcium, magnesium, aluminum, and tin. Examples include metal salts such as , salt, zinc, etc., and particularly preferred are calcium formate, barium formate, aluminum chloride, and the like. These latex-destroying agents destroy the emulsifier system used during emulsion polymerization to appropriately coagulate vinyl chloride latex, and by selecting a latex-destroying agent that improves the thermal stability during heating of the paste sol. , can have a favorable effect on molding. The amount of latex destroyer used varies depending on the type of latex destroyer, the type and amount of emulsifier present in the emulsifying system, the concentration of latex, the stirring conditions after adding the latex destroyer, the temperature, etc.
0.01 to 2 parts by weight per 100 parts by weight, preferably
About 0.05 to 1 part by weight may be sufficient. The thermal stability of the resulting paste sol can also be improved by selecting the latex-destroying agent. The addition of the oil-water separating agent is preferably carried out at the time of breaking the latex, and in particular, by using the oil-water separating agent and the latex breaking agent in combination, the paste resin and the aqueous phase can be quickly separated. On the other hand, the plasticizer may be added at the same time as the oil-water separation agent, after the oil-water separation, or before the oil-water separation. Preferably, it is most preferably added when the paste resin and aqueous phase begin to separate;
Separation of the paste sol and aqueous phase is observed in a short time. Furthermore, the timing of adding the plasticizer to the latex is set at a temperature at which the paste resin in the latex does not absorb the plasticizer quickly, for example, 40°C or lower, preferably 35°C or lower.
It is desirable that the temperature is below ℃. When plasticizers are added to latex at temperatures above 40°C, there is rapid absorption of the plasticizer into the paste resin, resulting in an increase in the viscosity of the plasticizer or, in extreme cases, gelation. This temperature varies depending on the composition of the paste resin in the applied latex; for example, straight homopolymers with a high degree of polymerization can be treated at temperatures above 40°C, e.g. 50°C; in the case of polymers or copolymers at relatively low temperatures, i.e.
Some items must be processed at temperatures below 35°C. Therefore, in the case of the method of the present invention, it is almost sufficient to keep the temperature of the latex below 35°C. In the method of the present invention, when adding a plasticizer, if necessary, a hydrophobic diluent such as texanol isobutyrate, dodecylbenzene, kerosene, mineral spirits, petroleum ether, petroleum benzine, ligroline, machine oil, benzene, toluene, xylene,
It is also possible to use monochlorobenzene or the like together with a plasticizer. However, if the diluent has low affinity with the paste resin, phase separation may not be successful. Therefore, it is desirable to add a diluent intended for the organosol after the paste sol is separated and taken out. There are no particular restrictions on the speed, time, etc. of stirring after adding the plasticizer to the latex.
This may be continued for several minutes to several tens of minutes until the paste sol phase and aqueous phase are completely separated. Since stirring requires a considerable amount of power, it is preferable to use a stirrer with slightly larger power.
Preferably, a mixing mixer such as that used for conventional plastisol compounding is used. The above-mentioned layer separation under stirring is easy, and after complete separation, the stirring is weakened or the mixture is allowed to stand still, and the upper aqueous phase is removed by decantation or the lower plasticizer phase is extracted to form a paste. Separate and take out the sol. The extracted paste sol is stirred and separated repeatedly by adding pure water as necessary to remove impurities such as emulsifiers, dispersants such as suspending agents, and electrolytes used to destroy the dispersion system. . Since the paste sol thus obtained may still contain a considerable amount of water, it is preferable to remove the water through a dehydration step. The dehydration method involves, for example, passing the paste sol through a simple three-roll roll or the like to separate most of the water, and then dehydrating it under reduced pressure. In order to remove water more effectively, a method is also adopted in which a suitable surfactant is added before dehydration by squeezing using three rolls. However, depending on the application, for example, when used for forming an extremely thin film, the above-mentioned dehydration step may be omitted. In addition, the paste sol produced by the method of the present invention also contains plasticizers, diluents, ultraviolet absorbers, colorants, heat stabilizers, antioxidants, blowing agents,
It goes without saying that additives (materials) used in ordinary paste sol, such as foaming aids and fillers, can be added as appropriate. According to the method for producing paste sol such as plastisol or organosol according to the present invention, vinyl chloride paste resin latex can be made into a sol without spray drying or pulverization, thereby preventing dusting and saving a large amount of energy that was previously required. is completely unnecessary, paste sol can be produced at low cost, and has extremely high industrial value in terms of energy saving and occupational health. Since the obtained paste sol is manufactured without going through a drying or pulverizing process, it does not contain hard agglomerated particles, has good heat gelling properties during molding, and has a glossy finish on the resulting molded product. At the same time, there is little discoloration due to heating. In addition, its physical properties are superior to those of conventional paste sol molded products at the same molding temperature. In addition, since the obtained product is a paste sol, there is no need to transport paste resin and plasticizer separately as in the past, and the transport method can be changed from powder transport and liquid transport to only liquid transport. Transportation by pipeline and tank truck becomes possible,
Significant advances are being made in transportation systems. Furthermore, for paste sol processing manufacturers, the operation of preparing paste sol has been simplified and can be done over a long period of time.
Stirring which requires high energy can be omitted, accessory equipment on the user side can be omitted, processing costs can be reduced, and the industrial value is extremely high. The method of the present invention will be explained below in detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. Example 1 After pre-emulsifying 100 parts by weight of vinyl chloride, 0.1 parts by weight of sodium lauryl sulfate and 0.15 parts by weight of lauroyl peroxide in water, polymerization was carried out at 45°C for 20 hours. The vinyl chloride paste resin latex obtained in this way has a particle concentration of 35% by weight and an average particle diameter of
It was 0.98μ. 1g of magnesium sulfate per 1000g of this latex
and 210 g of dioctyl phthalate and an oil-water separation agent represented by the general formula [] (12 moles of ethylene oxide, 120 moles of propylene oxide,
y/x=0.1, molecular weight approximately 7550) was added and stirred vigorously. When the stirring was stopped, the paste sol phase and the aqueous phase rapidly began to separate. The time required for complete separation of both phases and the water content in the sol 60 minutes after separation were measured (by heat of fusion measurement) and are shown in Table 1. After dehydrating 100 parts by weight of this paste sol under reduced pressure,
3 parts by weight of a Zn-based heat stabilizer was added and coated on a glass plate to a thickness of 200 μm, and left in an oven at 195° C. for 20 minutes. The obtained film was smooth, colorless and transparent, and had good dehydration properties and thermal stability. Example 2 A paste sol was produced in the same manner as in Example 1, except that magnesium sulfate was not used in Example 1, and the time required to separate the paste sol phase and aqueous phase and the water contained in the sol after 60 minutes of separation were It was measured and also listed in Table 1. The film manufacturing test results were also the same as in Example 1. Example 3 1 g of calcium formate was added to 1000 g of the same latex used in Example 1, and 210 g of dioctyl phthalate and an oil-water separating agent represented by the general formula [] (60 moles of propylene oxide, 6 moles of ethylene oxide, a+c/ b=0.1, molecular weight approx.
3800) and stirred vigorously. When stirring was stopped, the paste sol phase and aqueous phase began to separate rapidly. Time required for complete separation of both phases and separation 60
The water content in the sol after 1 minute was measured and is also listed in Table 1. A film was produced in the same manner as in Example 1, but
Even after being left at 195°C for 20 minutes, the obtained film was smooth and colorless and transparent.

[Table] Comparative Example 1 After adding 1 g of magnesium sulfate to 1000 g of the same latex used in Example 1, 210 g of dioctyl phthalate was added, followed by strong stirring and standing to produce a paste sol. After standing for 5 hours, the paste sol contained approximately 10% water, and dehydration under reduced pressure took time. After dehydrating under reduced pressure for the same time as in Example 1, 3 parts by weight of a Ca-Zn heat stabilizer was added to 100 parts by weight of the paste sol, and the mixture was applied to a thickness of 200μ on a glass plate.
Heated at 195°C. The obtained film had foaming due to evaporation of water, and its surface was uneven (commonly known as a toad skin), and its commercial value was slightly inferior. Example 4 A vinyl chloride paste resin latex was prepared according to Table 1 similar to Example 1 using ammonium myristate as an emulsifier. The particle size in the latex was 38% and the average particle size was 1.02μ. To 1,000 g of the latex were added 1 g of calcium formate, 210 g of dioctyl phthalate, and 0.1 g of the oil-water separation agent represented by the general formula [ ] used in Example 1, followed by stirring and water separation. Separation of the paste sol into the aqueous phase occurred immediately, and the water content of the sol was approximately 3% after 60 minutes of separation. The film was also subjected to a thermal stability test in the same manner as in Example 1, but even after being left in an oven at 195°C for 20 minutes, the film surface remained smooth and no discoloration was observed. Example 5 To 1000 g of the same latex used in Example 4, 1 g of ammonium formate and dioctyl phthalate were added.
After adding and stirring 210 g and 0.1 g of the oil-water separating agent represented by the general formula [] used in Example 3,
The paste sol phase and the aqueous phase were separated using a centrifuge (2000 rpm x 30 minutes). The water content in the sol was 1.2%. Example 6 Add 2 g of barium formate and 150 g of dioctyl phthalate to 1000 g of the same latex used in Example 4.
Add 0.1 g of an oil-water separating agent represented by the general formula [] (30 moles of propylene oxide, 4 moles of ethylene oxide, y/x≒0.13, molecular weight approximately 1970), stir at 800 rpm for 30 minutes, and then centrifuge. The paste sol phase and the aqueous phase were separated using a machine (3000 rpm x 30 minutes). The water content in the sol was 0.9%, and the paste resin was completely surrounded by plasticizer. Add 20g of plasticizer and Ba-Zn to 140g of the obtained sol.
After adding 5g of heat stabilizer and stirring, a film was produced in the same manner as in Example 1, but at 195℃ for 20 minutes.
The film remained colorless and transparent even after heating for a minute.

Claims (1)

[Claims] 1. In a method for directly producing a paste sol from a mixed system of vinyl chloride paste resin latex and a plasticizer, the mixed system has the general formula HO(C ₂ H ₄ O)a-(C ₃ H ₆ O)b- _{( C2H4O} )cH
...[] [In the formula, a+b+c is an integer from 20 to 110, a+c/
The ratio of b shows a value of 0.01 to 0.4. a and c may be different. ] or general formula [In the formula, x ₁ + y ₁ , x ₂ + y ₂ , x ₃ + y ₃ and x ₄ + y ₄ are,
Each integer from 5 to 60, y ₁ /x ₁ , y ₂ /x ₂ , y ₃ /x
and the average y/x ratio of the sum of y ₄ /x ₄ is 0.01 to 0.3
indicates the value of x ₁ , x ₂ , x ₃ and x ₄ and y ₁ , y ₂ , y ₃
and y ₄ may be the same number or different numbers. ] A method for producing a paste sol, which comprises containing an oil-water separating agent represented by: