JPS6333762B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a modified vinyl chloride-based graft copolymer, in particular a modified chloride-based graft copolymer that provides a soft molded product with good moldability, excellent matte appearance, and improved compression set and creep resistance. The purpose of this invention is to provide a vinyl-based graft copolymer. In recent years, soft molded products made of vinyl chloride resin have been given a matte appearance to give them a sense of luxury, and there is a high demand for this matte effect especially for automobile parts, electric wires, etc. It's summery. Conventionally, as a method of obtaining soft vinyl chloride resin molded products with a matte appearance, attempts have been made to give the molded product a matte effect by molding at a lower molding temperature than usual. If the molding temperature is lowered, kneading during molding will not be carried out sufficiently, resulting in a disadvantage that the molded product will have inferior properties such as mechanical strength. Note that when molding is carried out at the molding temperature normally employed for general vinyl chloride resins without lowering the molding temperature, a molded product with a matte appearance cannot be obtained. On the other hand, vinyl chloride resins have a high apparent degree of polymerization by blending vinyl chloride resin with a high degree of polymerization into heavy vinyl chloride, or by adding a crosslinking agent during polymerization of vinyl chloride. Attempts have been made to obtain matte molded products by making and using this as a molding resin. However, such resins with a high apparent degree of polymerization have extremely poor processability compared to general vinyl chloride resins, and for this reason, molding of such resins requires the use of special processing machines or special processing methods. The disadvantage is that it is difficult to obtain molded articles with the expected physical properties. In addition, although general vinyl chloride resins have good processability, they have the disadvantage of poor compression set and creep resistance. As a way to improve this,
There are methods to obtain products with a high apparent degree of polymerization by blending vinyl chloride resin with a vinyl chloride polymer or by adding a crosslinking agent during polymerization of vinyl chloride. As mentioned above, vinyl chloride resins with a high apparent degree of polymerization have the disadvantage that their processability is extremely poor, which limits their application fields and scope of use, and the expected physical property effects are also small. . In addition, in order to manufacture vinyl chloride resin with a high degree of polymerization, it is necessary to polymerize it at a lower polymerization temperature than when obtaining ordinary resin, so special conditions such as selection of polymerization initiator and production equipment are required. It has the disadvantage that it is necessary and not easy to manufacture. The present inventors solved the conventional disadvantages,
The present invention was completed as a result of intensive research to obtain a molded product with good molding processability, excellent matte effect, and excellent compression set. (In the formula, R ¹ and R ² are monovalent hydrocarbon groups, n is an integer.) A copolymer with a carbonate compound represented by or a mixture of at least one of these monomers and a polymerizable compound having two or more unsaturated bonds in one molecule. The present invention relates to a method for manufacturing a combination. According to the present invention, it is possible to obtain a molded product that does not have the above-mentioned disadvantages, has good workability, and has an excellent matte appearance, and at the same time has good deformation resistance as represented by compression set. The advantage is that it is greatly improved. To explain in more detail below, the copolymer to be used as the backbone polymer for graft polymerization used in the method of the present invention is a copolymer of vinyl chloride monomer and a carbonate compound represented by the above general formula. However, this carbonate compound is used to introduce a suitable amount of crosslinking into the copolymer that becomes the backbone polymer, thereby achieving the desired matting effect and improving compression set and creep resistance. Therefore, it is desirable to use it in the range of 0.1 to 5% by weight based on the vinyl chloride monomer. If it is used in an amount exceeding 5% by weight, chain transfer properties of the carbonate compound will appear strongly, and the resulting polymer will has a small degree of polymerization, and the degree of crosslinking also becomes small. On the other hand, if it is less than 0.1% by weight, the above-mentioned effects due to the introduction of crosslinking bonds cannot be expected, and the graft polymerization described below will not proceed smoothly. Specific examples of the carbonate compound used for this purpose include methylallyl peroxycarbonate, ethyl-3-methyl-3-butenyl peroxycarbonate, and tert-butyl-3-methyl-3-butenyl. Peroxycarbonate, tert-butyl-3-ethyl-3
-Butenyl peroxycarbonate, isopropyl-3-butenyl peroxycarbonate, methyl-2-methyl-2-propenyl peroxycarbonate, propyl-4-ethyl-4-pentenyl peroxycarbonate, tert-butylallyl peroxycarbonate , ethyl-3-ethyl-3-butenyl peroxycarbonate, neodecylallyl peroxycarbonate, and the like. These are not limited to one type, and two or more types may be used simultaneously. Note that other comonomers may be used together with the carbonate compound as long as the original characteristics of the vinyl chloride resin are not lost, and these include vinyl acetate, vinyl caproate, vinyl laurate,
Vinyl esters such as vinyl stearate, olefins such as ethylene, propylene, and isobutylene, alkyl vinyl ethers such as isobutyl vinyl ether, octyl vinyl ether, dodecyl vinyl ether, and phenyl vinyl ether, vinylidene chloride, vinyl fluoride, propylene chloride,
Halogenated olefins such as vinyl bromide, acrylic acid and methacrylic acid esters such as ethyl acrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, acrylic acid, methacrylic acid , crotonic acid, acrylonitrile, maleic anhydride, itaconic anhydride, and other acrylic derivatives. These are not limited to one type, and two or more types may be used simultaneously. As a method for copolymerizing the vinyl chloride monomer with the above-mentioned carbonate compound, any method such as suspension polymerization method, solution polymerization method, or bulk polymerization method may be used, but suspension polymerization method is generally used industrially. Economically advantageous. The polymerization temperature is preferably in the range of 30 to 65°C. The method for adding the carbonate compound is not particularly limited and various methods can be employed, but it is preferable to add it as an emulsion or a solution. Furthermore, the timing of addition to the polymerization system is not limited to the case where it is added and blended from the beginning, but may be added in several portions or continuously after the polymerization reaction has started. The suspension stabilizer, polymerization initiator, etc. used when carrying out the above polymerization by the suspension polymerization method may be those normally used in the polymerization of vinyl chloride monomers. For example, as a suspension stabilizer, Fully saponified or partially saponified polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, synthetic polymers such as maleic anhydride-vinyl acetate copolymer, starch, gelatin, etc. (These are not limited to one type, but two or more types may be used in combination). Examples of polymerization initiators include decanoyl peroxide, lauroyl peroxide,
Benzoyl peroxide, di(isopropyl)
Peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, diacyl peroxides such as acetylcyclohexylsulfonyl peroxide, peroxyesters such as tert-butyl peroxypivalate, tert-butyl peroxyneodecanate, etc. organic peroxides, and α,α′-azobisisobutyronitrile, α,α′-azobis-2,4-dimethylvaleronitrile, α,α′azobis-4-methoxy-
Examples include azo compounds such as 2,4-dimethylvaleronitrile (these are not limited to one type, but two or more types may be used in combination). The method of the present invention includes adding at least one monomer selected from acrylic acid ester, methacrylic acid ester, styrene monomer, and acrylonitrile to the copolymer to be the backbone polymer described above, and adding two monomers in one molecule. The desired vinyl chloride-based graft copolymer is obtained by graft polymerizing a mixture with a polymerizable compound having more than one unsaturated bond, and the monomer used in this case is acrylic acid. Acrylic acid esters such as ethyl, isobutyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, methacrylate Examples include methacrylic acid esters such as stearyl acid, styrene monomers such as styrene, methylstyrene, α-methylstyrene, and dichlorostyrene, and acrylonitrile. On the other hand, specific examples of polymerizable compounds include diallyl esters of phthalic acid such as diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl esters of phthalic acid such as diallyl maleate, diallyl terephthalate, diallyl maleate, diallyl fumarate, Diallyl and divinyl esters of ethylenically unsaturated dibasic acids such as diallylitaconate, divinyl itaconate, divinyl fumarate; diallyl and divinyl esters of saturated dibasic acids such as diallyl adipate, divinyl adipate, diallyl azelate, diallyl sebacate; , diallyl ether, triallyl cyanurate, triallyl isocyanurate,
triallyl trimellitate and divinyl ethers such as ethylene glycol divinyl ether, n-butanediol divinyl ether, and octadecane divinyl ether; acrylic and methacrylic acids such as vinyl acrylate, vinyl methacrylate, allyl acrylate, and allyl methacrylate; Vinyl and allyl esters, diacrylic and dimethacrylic esters of polyhydric alcohols such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethalate , triacrylic and trimethacrylic esters of polyhydric alcohols such as trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate, bismethacryloyloxyethylene phthalate, 1,3,5-triacryloylhexahydrotriazine, and Examples include low molecular weight polymers containing unsaturated bonds such as 1,2-butadiene homopolymer. Note that these are not limited to one type, and two or more types may be used simultaneously. The combined ratio of the monomer component and the polymerizable compound is such that the polymerizable compound is 1 to 40% by weight of the monomer component amount.
A significant amount is required. If it is less than 1%, the crosslinking effect will be small, and if it is more than 40%, crosslinking will proceed too much, resulting in excessive crosslinking and making processing difficult. By graft-polymerizing a mixture of such a monomer and a polymerizable compound, the resulting graft copolymer has improved gelling properties in soft formulations,
Further, the dispersibility of the gel content is improved, both processability and physical properties are improved, and the desired advantage is that the desired excellent matte molded product can be easily obtained. If this graft polymerization is not carried out, both the gelation property and the dispersibility of the gel content will become unstable due to a slight change in the gel content (the amount of crosslinking introduced), and the surface of the molded product will likely become pear-like. The graft polymerization may be carried out by a conventionally known method. For example, the copolymer (stem polymer) is produced by a suspension polymerization method, and after the polymerization is completed, the components to be grafted are added to the slurry system. After adding the specified amount and polymerization initiator, the polymerization temperature is approximately
The desired graft copolymer can be obtained by graft polymerization at 70 to 100°C. The ratio of the graft component to the backbone polymer is 100% of the backbone polymer.
It is desirable that the amount of the graft component be 1 to 100 parts by weight (preferably 10 to 100 parts by weight) based on the weight of the graft component.
If the amount of this graft component is less than 1 part by weight, the above-mentioned effects such as improving processability cannot be sufficiently obtained, and if it is more than 100 parts by weight, the graft copolymer obtained will lose the properties inherent to vinyl chloride resin, and it will become slippery during processing. This has the disadvantage that it may not be possible to knead it because of its too high properties. The vinyl chloride-based graft copolymer obtained by the method of the present invention has almost the same processability as general vinyl chloride resin, and has a soft formability with excellent compression set, improved creep resistance, and a matte appearance. Plasticizers used to obtain such soft molded products include alkyl esters of aromatic polybasic acids such as dibutyl phthalate, dioctyl phthalate, and butylbenzyl phthalate; Alkyl esters of aliphatic polybasic acids such as dioctyl adipate, dioctyl azelate, dioctyl sebacate,
Examples include phosphoric acid alkyl esters such as tricresyl phosphate. In addition, lead-based stabilizers such as tribasic lead sulfate, tin-based stabilizers such as dibutyltin malate, heat stabilizers exemplified by metal soaps such as zinc stearate and calcium stearate, carbon black, calcium carbonate, and titanium oxide. , fillers such as talc, asbestos, aluminum hydroxide, magnesium hydroxide, pigments such as color carbon black, chrome yellow, titanium oxide, phthalocyanine green, etc., other antistatic agents, dropless agents, and ultraviolet absorbers. Adding agents etc. is optional. As described above, the modified vinyl chloride graft copolymer according to the present invention can be molded by
It can be blended, kneaded and molded in the same steps as conventional vinyl chloride resins, and may be supplied in either pellet or powder form. Furthermore, the molding conditions are no different from those of conventional vinyl chloride resins, and the above-mentioned excellent molded products can be easily obtained. Next, a specific example will be given. Example The following components were charged into a stainless steel polymerization vessel with an internal volume of 50 mm, and a polymerization reaction was carried out at 50°C for 10 hours. Pure water 30Kg Vinyl chloride monomer AKg Carbonate compound BKg Total 15Kg Partially saponified polyvinyl alcohol 20g Di-2-ethylhexyl peroxycarbonate
7.5g (The type of carbonate compound and each amount of A and B are listed in the table.) Next, the graft monomer and the polymerizable compound were added to the predetermined amount of the copolymer slurry obtained by the above polymerization. They were added in the proportions shown below, and a graft polymerization reaction was carried out at 80°C for 4 hours. Copolymer slurry 12Kg as solid content Graft monomer CKg Polymerizable compound Part D (Types of graft monomer and polymerizable compound,
The amounts of C and D are listed in the table; however, part D of the polymerizable compound is the number of parts per 100 parts by weight of the graft monomer). After graft polymerization as described above, the polymers were washed with water and dehydrated and dried to obtain vinyl chloride-based graft copolymers having gel contents (% by weight) as shown in the table. [Measurement method for gel content in copolymer] 1.00 g of sample was added to 100 ml of tetrahydrofuran (THF), dissolved by shaking at the boiling point of THF for 60 minutes, undissolved content was centrifuged, and the amount was calculated from its dry weight. Dioctyl phthalate was added to 100 parts by weight of the vinyl chloride graft copolymer produced as described above.
80 parts by weight, 2 parts by weight of calcium stearate, and 5 parts by weight of epoxidized soybean oil were blended and kneaded for 10 minutes after being rolled at 160°C using a 3-inch roll.
At this time, the roll winding time (seconds) and the state of the sheet surface (rolled sheet) wound around the roll were observed. [Measurement of roll winding time (seconds)] The time (seconds) from when the mixture was put on the roll to when the mixture appeared to be gelled on the roll surface was measured using a stopwatch. Next, add carbon black to the above formulation.
The mixture to which 0.2 parts by weight was added was extruded into a sheet using a 20 mmφ extruder, and the surface condition of this sheet (extruded product) was observed. On the other hand, preheat the roll sheet to 185℃ for 7 minutes, 30 minutes.
Compression set was measured for a product that was press-formed under Kg/cm ² pressure for 4 minutes. [Measurement of compression set] Based on JIS K 6301, measurement was carried out under the conditions of 25% compression at 70°C for 22 hours. The results were as shown in the table. As is clear from these results, the method according to the present invention has good molding processability, matte state, and compression set. Particularly, when a polymerizable compound is used in conjunction with graft polymerization, the processability, matt state, and compression set are good. Distortion becomes even better. [Abbreviations used in the table] 1 Carbonate compound BAPC: t-butyl allyl peroxycarbonate DAPC: Neodecyl allyl peroxy carbonate BEPC: t-butyl-3-ethylbutynyl peroxy carbonate 2 Graft monomer AEH: 2-Ethylhexyl acrylate MST: α-methylstyrene ST: Styrene MAB: Butyl methacrylate 3 Polymerizable compound DAP: Diallyl phthalate DAM: Diallyl maleate BHP: 1,2-butadiene homopolymer DAI: Diallyl itaconate PEA: Polyethylene glycol Diacrylate MAB: Vinyl methacrylate.

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Claims (1)

[Claims] 1. Vinyl chloride monomer and general formula (In the formula, R ¹ and R ² are monovalent hydrocarbon groups, n is an integer) and a copolymer with a carbonate compound selected from acrylic esters, methacrylic esters, styrene monomers, and acrylonitrile. It is characterized by graft polymerizing a mixture of at least one monomer and a polymerizable compound having two or more unsaturated bonds in one molecule in an amount equivalent to 1 to 40% by weight based on the amount of the monomer. A method for producing a vinyl chloride-based graft copolymer.