JPH0254851B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses vinyl chloride polymers (hereinafter referred to as PVC).
) and other specific polymers are finely dispersed in the unmelted stage before normal kneading processing, and are easily processed and have excellent transparency and other physical properties. The present invention relates to a method for producing a polymer. In addition to its excellent physical and mechanical properties, PVC is also used in large quantities for building materials, cable sheathing materials, vehicles, etc. due to its economic efficiency. In particular, by blending plasticizers such as phthalate esters and adipate esters with PVC, molded products that are flexible and elastic at room temperature can be obtained, which is a feature unparalleled by other resins, and its uses are wide. I'm making it a thing. However, depending on the application, impact resistance, heat deformation resistance, etc. are not necessarily sufficient. In addition, soft PVC compositions plasticized with plasticizers have the disadvantage that the plasticizers volatilize and age, or migrate to other parts and cause harm. Attempts have been made to improve the above drawbacks by mixing other polymers during processing or by graft polymerizing vinyl chloride with other polymers. However, with the former method, it is extremely difficult to obtain a composite in which PVC and other polymers are finely dispersed, and physical properties such as strength and transparency are not sufficiently exhibited.
Furthermore, in the latter method, the reaction may not proceed depending on the polymer used, or crosslinking reactions or deterioration may occur during the reaction, making it impossible to obtain desired physical properties. As a result of studies to overcome the various drawbacks mentioned above, the inventor of the present invention has discovered that by mixing small-sized granular PVC and other specific polymers under specific conditions, both particles can be made fine. The inventors have discovered that it is possible to obtain a powder-like composite polymer that is dispersed in , has good processability, and has excellent transparency and other physical properties, and has completed the present invention based on this knowledge. That is, the present invention provides granular PVC (A), ethylene-vinyl acetate-carbon monoxide ternary copolymer, and/or thermoplastic polyurethane (hereinafter sometimes referred to as other polymer) with an average particle size of 40 μm or less ( B), and a solvent (C) for (B) that is incompatible with water and is a poor solvent for (A).
After mixing in an aqueous medium, (C) is removed, dehydrated,
By drying, PVC (A) and other polymers (B)
The present invention provides a method for producing a powdery composite polymer comprising: The granular PVC (A) used in the present invention is a homopolymer of vinyl chloride, a copolymer of vinyl chloride and another monomer copolymerizable with it, or a copolymer of vinyl chloride and another polymer. Examples include graft copolymers of. However, these granular PVC
The average particle size of (A) needs to be 40 μm or less, preferably 20 μm or less. If the particle size of PVC(A) exceeds the above range, ungelled particles will be present in the obtained composite polymer processed product, which will worsen the appearance of the product and reduce its strength, which is undesirable. .
Such PVC(A) may be produced by any method such as emulsion polymerization, suspension polymerization, bulk polymerization, or gas phase polymerization, but the above-mentioned production method that gives fine particles may be used. Advantageous methods include emulsion polymerization, homogeneous polymerization using a pressure homogenizer, and suspension polymerization using special dispersants or surfactants. (A) may be in the form of a dehydrated or dried product, or in the form of a slurry or latex after the polymerization reaction has been completed. Further, the degree of polymerization of PVC(A) is usually 300 to 5000. Other polymers (B) used in the present invention are limited to ethylene-vinyl acetate-carbon monoxide terpolymer and/or thermoplastic polyurethane. If a polymer other than these is used, only a composite polymer having some drawbacks such as transparency, strength, flexibility, etc. can be obtained. Ethylene-vinyl acetate used in the present invention
The composition of the carbon oxide terpolymer is generally 40-80% by weight of ethylene, 10-60% by weight of vinyl acetate, and 3-30% by weight of carbon monoxide. Such terpolymers are already known, and some are commercially available. The thermoplastic polyurethane used in the present invention has a molecular weight of 300 or more, preferably 500 or more, and is obtained from a long chain glycol having hydroxyl groups at both ends and a polyisocyanate having NCO groups at both ends, and is commercially available. It is fine to use the one that has been published. The amount of the other polymer (B) used in the present invention is 10 to 500 parts by weight, based on 100 parts by weight of PVC (A).
Preferably it is 20 to 300 parts by weight. If (B) is less than 10 parts by weight, the resulting composite polymer will have poor flexibility, while if it exceeds 500 parts by weight, it will be too soft or have defects in physical properties. Solvents (C) for other polymers used in the present invention
is not particularly limited as long as it is incompatible with water, is a poor solvent for PVC, and dissolves other polymers; for example, halogens such as vinyl chloride, vinyl fluoride, vinyl bromide, etc. Examples include vinyl chloride, vinylidene chloride, cyclohexane, and benzene. Of course, it is also possible to use two or more of these in combination. Among these, vinyl chloride is
It is extremely preferable because it has polarity, so there is a wide range of options for other polymers, its low boiling point makes it difficult to remain in the polymer, and it is easy to recover, and it is inexpensive and easily available. The amount of (C) used is 30 to 1000 parts by weight per 100 parts by weight of other polymers. The method of mixing the polymers in the present invention is not particularly limited, and examples include a method of mixing PVC, another polymer, and a solvent in the presence of an aqueous medium, a method of mixing the other polymer in advance as a solvent solution, and then mixing the PVC and There are methods such as mixing with water, but the method may be selected as appropriate depending on the solubility of the other polymer in the solvent. The amount of water used in the present invention is usually at least 50 parts by weight, preferably at least 100 parts by weight, per 100 parts by weight of PVC and other polymers. If the amount is less than 50 parts by weight, PVC will stick to other polymers dissolved in (C) and become block-like, making it impossible to obtain a granular composite polymer. The upper limit of the amount of water is not particularly limited, but in general, when using a large amount of water exceeding 500 parts by weight per 100 parts by weight of PVC and other polymers, the composite obtained in one production The efficiency is poor because the amount of polymer is small. The aqueous medium in the present invention may contain 0 to 10 parts by weight, preferably 0.001 to 5 parts by weight of a dispersant or emulsifier per 100 parts by weight of PVC and other polymers. When the amount of other polymers used is relatively large, it is preferable to coexist a dispersant or emulsifier. Note that since the PVC slurry or latex after polymerization contains a dispersant or emulsifier, it may be convenient to use it as it is. Dispersants that may be used in the present invention include, for example, partially saponified polyvinyl acetate,
Cellulose derivatives such as alkylcellulose, polyelectrolytes such as polyvinylpyrrolidone, polyacrylic acid, and polyacrylates, maleic anhydride
Examples include synthetic water-soluble polymeric substances such as vinyl acetate copolymers, natural polymeric substances such as starch, gelatin, gum tragacanth, or mixtures of one or more thereof. As emulsifiers, sorbitan monolaurate, sorbitan triolate,
Partial esters of polyhydric alcohols such as glyceryl monostearate, ethers such as polyoxyethylene nonyl phenyl ether, polypropylene glycol-polyethylene glycol block copolymers, nonionic surfactants such as higher alcohols; Sodium stearate , higher fatty acid salts such as potassium oleate, sodium alkyl sulfates such as sodium lauryl sulfate, sodium alkylallylsulfonates such as sodium dodecylbenzenesulfonate, and anionic surfactants such as sodium alkylsuccinates. It will be done. In the present invention, an autoclave equipped with a stirrer is used as a container for mixing PVC, other polymers, and solvents for other polymers. The temperature of mixing varies depending on the type and amount of other polymers, but typically
The temperature ranges from room temperature to 80°C. Further, stirring conditions do not need to be particularly limited, and conditions may be selected that allow the mixture to flow and disperse. Mixing time is 30 minutes to 3 hours. If necessary, common plasticizers, stabilizers, ultraviolet absorbers, antioxidants, lubricants, pigments, fillers, reinforcing agents, etc. can be added during this mixing. In addition, in order to obtain powder of appropriate size, acid,
Alkali, salt, coagulant, etc. can be added. In this way, according to the present invention, a composite polymer with excellent physical properties can be obtained with a relatively simple mixing operation. Next, the present invention will be explained with reference to Examples, in which the parts and percentages shown are based on weight. In addition,
Sample preparation and physical property measurements in Examples were performed as follows. (1) Preparation of sample To 100 parts of composite polymer, add 0.2 parts of calcium stearate, 0.3 parts of zinc stearate, and 5 parts of epoxidized soybean oil, roll knead the mixture at 140°C for 5 minutes to prepare a sheet, and heat stabilize it. It was subjected to a sex test.
In addition, this rolled sheet was pressed at 145℃ and a pressure of 50Kg/ ^cm2 for 5 minutes, and was subjected to a tensile test, a transparency test,
It was used for hardness measurement and measurement of ungelled particles. (2) Weight average particle size of PVC Measured using a Coulter Counter manufactured by Coulter. (3) Transparency The transmittance of light at a wavelength of 600 nm was measured. (4) Number of ungelled particles A press sheet with a thickness of 0.2 mm is enlarged and projected 10 times using a projector, and a certain area of unmelted particles is projected on the screen.
PVC particles were counted and converted to number per cm ² . (5) Tensile test Method described in JIS K6723. (6) Hardness Method described in JIS K6301. (7) Thermal stability A test piece was prepared from a roll sheet, heated to 180°C in a gear oven, and judged based on the time until discoloration. Example 1 Water was added to a stainless steel autoclave equipped with a stirrer.
300 parts, hydroxypropyl methylcellulose 0.5
parts, 0.3 parts of aluminum sulfate, 50 parts of vinyl chloride polymer with a degree of polymerization of 1000 and an average particle size of 0.7 μm, ethylene-
50 parts of pellets of vinyl acetate-carbon monoxide terpolymer (Elvaloy 741, manufactured by DuPont) and 50 parts of vinyl chloride monomer were added, and after stirring at 40°C for 1 hour, the vinyl chloride monomer was recovered. A powdery composite polymer was obtained by dehydration and drying. Example 2 A copolymer latex with an average particle size of 1.6 μm and consisting of 98 parts of vinyl chloride and 2 parts of lauryl vinyl ether was added to a copolymer latex with an average particle size of 1.6 μm.
Per 50 parts, 50 parts of the same ethylene-vinyl acetate-carbon monoxide ternary copolymer used in Example 1, 0.5 part of calcium hydroxide, and 50 parts of vinyl chloride monomer were added.
After stirring at 40° C. for 1 hour, the vinyl chloride monomer was collected, dehydrated, and dried to obtain a powder composite polymer. Example 3 Water was added to a stainless steel autoclave equipped with a stirrer.
500 parts hydroxypropyl methylcellulose 4
parts, 0.2 parts of sodium dodecylbenzenesulfonate,
Add 0.1 part of di-2-ethylhexyl peroxydicarbonate, add 200 parts of vinyl chloride monomer after degassing, start polymerization at 58°C, and when the polymerization rate reaches 60%, add ditertiary butyl hydrocarbonate. toluene
Polymerization was stopped by adding 0.04 parts. Half of the resulting slurry was mixed with 60 parts of water, 60 parts of the same ethylene-vinyl acetate-carbon monoxide terpolymer used in Example 1, and 20 parts of vinyl chloride monomer with a separate stirrer. The mixture was transferred to a stainless steel autoclave, stirred at 40°C for 1 hour, vinyl chloride was recovered, dehydrated, and dried to obtain a powder composite polymer. Incidentally, after recovering unreacted vinyl chloride from the slurry remaining in the first autoclave, the average particle size of the vinyl chloride polymer obtained by dehydration and drying was measured and found to be 26 μm. Example 4 Instead of the ethylene-vinyl acetate-carbon monoxide terpolymer used in Example 2, 40 parts of thermoplastic polyurethane (Pandex T-5265, a product of Dainippon Ink Industries, Ltd.) and A powder composite polymer was obtained in the same manner as described in Example 2, except that 60 parts of the copolymer was used in the same vinyl chloride copolymer latex as used. Example 5 200ml of water in a stainless steel autoclave with a stirrer
1 part of partially saponified polyvinyl acetate, 60 parts of PVC obtained in Example 3, 40 parts of the same thermoplastic polyurethane as used in Example 4, and 40 parts of vinyl chloride were added, and the mixture was stirred at 40°C for 1 hour. The vinyl chloride monomer was recovered and dehydrated and dried to obtain a powdery composite polymer. Example 6 Water was added to a stainless steel autoclave equipped with a stirrer.
200 parts, 50 parts of granular PVC obtained in Example 3, 0.2 parts of hydroxymethyl cellulose, 20 parts of the same ethylene-vinyl acetate-carbon monoxide terpolymer used in Example 1, the same as used in Example 4. After adding 30 parts of thermoplastic polyurethane and 50 parts of vinyl chloride monomer and stirring at 40°C for 1 hour, the vinyl chloride monomer was recovered, dehydrated, and dried to obtain a powder composite polymer. The physical properties of the composite polymers obtained in Examples 1 to 6 were measured. The results were as shown in Table 1. It can be seen from Table 1 that all of the inventive samples of Examples 1 to 6 are transparent, have few ungelled particles, and provide flexible composite polymers with excellent strength and thermal stability. Comparative Example 1 Instead of the ethylene-vinyl acetate-carbon monoxide ternary copolymer used in Example 3, 60 parts of a copolymer of 55% ethylene and 45% vinyl acetate (Levaprene 450N, manufactured by Bayer) was used. A powder composite polymer was obtained in the same manner as described in Example 3 except for this. The physical properties of this composite polymer are shown in Table 2, and this composite polymer using ethylene-vinyl acetate copolymer has inferior transparency and strength compared to the composite polymer of Example 3. Ta. Comparative Example 2 Instead of PVC used in Example 1, polymerization degree of 1000,
Except for using powdered PVC with an average particle size of 120 μm.
A powder composite polymer was obtained by the same method as described in Example 1. The physical properties of this composite polymer are shown in Table 2, and compared to the composite polymer of Example 1, it contained more ungelled particles and was inferior in strength. Comparative Example 3 50 parts of the same granular PVC used in Example 1 and 50 parts of ethylene-vinyl acetate-carbon monoxide terpolymer
Comparative Example 4 Physical properties of 60 parts of the same PVC used in Example 4 mixed with 40 parts of thermoplastic polyurethane using a roll. was measured. The results are shown in Table 2, and compared to the composite polymer of Example 5, there were more ungelled particles and the strength was inferior. Comparative Example 5 50 parts of the same ethylene-vinyl acetate-carbon monoxide ternary copolymer used in Example 1, 0.3 parts of partially kelized polyvinyl acetate, and 0.3 parts of hydroxypropyl methylcellulose were added to a stainless steel autoclave equipped with a stirrer. After degassing, add 120 parts of vinyl chloride monomer and stir at 40°C for 1 hour, then add 0.1 part of t-butyl peroxypivalate and start polymerization at 58°C.
When the vinyl chloride portion in the produced polymer reaches 50%, ditertiary butyl hydrotoluene
0.02 part was added to stop the polymerization, and after recovering unreacted vinyl chloride monomer, it was dehydrated and dried to obtain graft polymer particles. The physical properties of this polymer particle are shown in Table 2, and compared to the composite polymer of Example 1, it had poor flexibility and poor thermal stability. Comparative Example 6 40 parts of the polyurethane used in Example 4, 200 parts of water, 0.3 parts of hydroxypropyl methyl cellulose, and 0.3 parts of partially saponified polyvinyl acetate were added to a stainless steel autoclave equipped with a stirrer, and after degassing, the vinyl chloride monomer was added. 68.6 parts and lauryl vinyl ether
After adding 1.4 parts and stirring at 40°C for 1 hour, 0.05 part of di-2-ethylhexyl peroxydicarbonate was added and polymerization was started at 58°C until the vinyl chloride and lauryl vinyl ether moieties in the resulting polymer reached 60%. At the point when the mixture had dried, 0.01 part of ditertiary butylhydrotoluene was added to stop the polymerization, and unreacted monomers were collected, dehydrated, and dried to obtain graft polymer particles. The physical properties of this polymer particle were measured. The results are shown in Table 2, and the thermal stability was significantly inferior to that of the composite polymer of Example 4.

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Claims (1)

[Claims] 1 A granular vinyl chloride polymer (A) with an average particle size of 40 μm or less, an ethylene-vinyl acetate-carbon monoxide ternary copolymer and/or a thermoplastic polyurethane (B), and is incompatible with water, and Solvent of (B) that is a poor solvent of (A)
After mixing (C) in an aqueous medium, (C) is removed, dehydrated, and dried to produce a powdered composite polymer consisting of (A) and (B). A method for producing a characteristic composite polymer.