JP2000319480A - Production of graft copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably produce a graft copolymer having highly stable qualities at a high production efficiency by bringing a part or the whole of a monomer mixture into contact with an aqueous medium and a surfactant and then supplying the mixture into a polymerizer wherein to polymerize it. SOLUTION: A rubbery polymer is produced by dispersing 100 pts.wt. monomer mixture containing 55-100 wt.% 2-12C alkyl acrylate in 8-200 pts.wt. aqueous medium containing 0.02-3 pts.wt. surfactant and adding a polymerization initiator to the resultant dispersion to cause the polymerization. The objective graft copolymer is produced by adding 70-5 pts.wt. monomer mixture (e.g. a 1-12C alkyl methacrylate, 2-12C alkyl acrylate and an aromatic vinyl) which, when polymerized alone, gives a hard polymer having a glass transition point of 20 deg.C or higher to a latex containing 30-95 pts.wt. rubbery polymer to cause the graft copolymerization of the monomer mixture. The monomer mixture is added to the latex in the form of a dispersion in an aqueous medium containing a surfactant. A resin composition is formed by compounding 100 pts.wt. thermoplastic resin (e.g. a vinyl chloride resin) with 1-70 pts.wt. graft copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a graft copolymer. More specifically, when producing a graft copolymer by an emulsion polymerization method, there are few impurities remaining in the obtained graft copolymer, and an extremely small amount of scale is generated at the time of polymerization. And a method for producing a graft copolymer. The present invention further provides a graft copolymer produced by the production method,
And a thermoplastic resin composition containing the graft copolymer,
Furthermore, it relates to the molded product.

[0002]

2. Description of the Related Art Vinyl chloride resin, chlorinated vinyl chloride resin, acrylic vinyl chloride resin, methyl methacrylate resin, acrylonitrile-styrene resin, methyl methacrylate-styrene resin, styrene resin, polycarbonate resin, polyester resin, polyether resin, cycloolefin Rigid polymers such as copolymer resins have been widely used in various fields as resin molding materials because of their good mechanical properties and chemical properties and good processability. However, when used as a molding material in the form of a simple substance of these resins or a mixture of these resins, there is a disadvantage that the impact resistance is not sufficient (the above-mentioned “simple substances of these resins or a mixture of these resins”). Includes not only the resin or a mixture of the resins, but also a composition of the resin in which a stabilizer, a lubricant and a filler are blended).

Therefore, in order to improve the impact resistance of the resin, a so-called polymer alloy technique in which rubber-like polymer fine particles of submicron to micron diameter are dispersed in the resin matrix has been widely used. Specifically, a rubbery trunk polymer such as a diene-based or alkyl acrylate-based polymer is added to an alkyl methacrylate monomer, an alkyl acrylate monomer, an aromatic vinyl monomer, and a vinyl cyanide monomer. There is known a method in which a graft copolymer obtained by graft polymerization of a product or the like is mixed with the resin. These graft copolymers are widely used as impact modifiers for improving the impact resistance without impairing the properties of the resin to be mixed. For example, impact modifiers used for vinyl chloride resin (PVC) are required to significantly improve the impact resistance of PVC without impairing the excellent chemical resistance and processability of PVC. As described above, a graft copolymer has been used as an impact resistance improver capable of satisfying both requirements, and many improvements have been studied for the production method thereof.

Conventional methods for producing a graft copolymer include:
Several methods are known, such as an emulsion polymerization method, a microemulsion polymerization method, a dispersion polymerization method, a suspension polymerization method, and a radiation polymerization method. In particular, an emulsion polymerization method is suitable as a method for producing fine graft copolymer particles having a submicron diameter and further for producing graft copolymer particles having a higher-order structure represented by a core-shell structure. ing.

In the emulsion polymerization method, the polymerization reaction usually proceeds in a surfactant micelle provided by a surfactant. The polymer produced as the polymerization proceeds is insoluble or hardly soluble in water, but is dispersed stably in the aqueous medium as fine particles without separation or coagulation from the aqueous medium due to the action of the surfactant. Exist. Such a polymer dispersion is called a latex. Particles formed mainly of a polymer dispersed and present in the latex may be referred to as latex particles.

[0006] The polymer obtained by the emulsion polymerization method is obtained by spray-drying the polymer latex after the polymerization is completed, or after coagulation by adding an electrolyte, an acid, or the like to the polymer latex, from an aqueous medium. By separating and drying, the powder can be isolated and recovered as a powder. Further, after coagulation by adding an electrolyte or an acid to the latex, it can be recovered in the form of pellets by extrusion and drying. Also in the production of the graft copolymer, after synthesizing a latex containing polymer particles by an emulsion polymerization method,
As described above, a method for isolating and recovering a graft copolymer from an aqueous medium is widely used.

[0007] For the method of producing the latex containing the graft copolymer by an emulsion polymerization method, the following procedure is usually used in more detail. That is,
First, a monomer or monomer mixture having a composition giving a rubbery polymer is emulsion-polymerized in one or more stages to synthesize a rubbery trunk polymer serving as a core portion, and then a monomer having a composition giving a hard polymer is obtained. The latex of the graft copolymer is manufactured by synthesizing a shell layer by emulsion polymerization of a monomer or monomer mixture in one or more stages. When emulsion-polymerizing a monomer or monomer mixture having a composition for providing a rubbery polymer and / or a monomer or monomer mixture having a composition for providing a hard polymer, the polymerization reaction rate must be controlled. For the purpose of controlling the polymerization reaction heat safely by controlling the polymerization reaction rate and controlling the latex temperature inside the polymerization tank, the quality of the graft copolymer is further controlled by controlling the polymerization tank internal temperature by controlling the polymerization reaction rate. In most cases, the amount of monomer or monomer mixture is limited due to the transfer capacity of the equipment for transferring the monomer or monomer mixture from the storage facility for monomer or monomer mixture to the polymerization tank. The body or monomer mixture is continuously fed to the polymerization vessel at a preset additional rate. Such a method in which a monomer or a monomer mixture is continuously supplied to a polymerization tank at a predetermined additional rate to perform emulsion polymerization is referred to as continuous emulsion polymerization. The monomer or monomer mixture is, for example, a gas at normal pressure in a temperature range (0 to 100 ° C.) where water is a liquid (for example, butadiene or vinyl chloride). In many cases, a continuous emulsion polymerization method is used in the production of the graft copolymer as described above, except in cases where it is difficult to stably and continuously supply the above.

When producing a polymer by an emulsion polymerization method,
Often, the problem of latex stability degradation occurs. Especially during the polymerization process, since the monomer coexists in the latex, the monomer may be present in the latex particle in a state where the polymer is impregnated in the latex particle. Become In addition, mechanical shear such as stirring to mix the reaction solution, electrolytes, acids and bases used as auxiliary materials to control the polymerization reaction and various physical properties of the obtained particles, and other unintentionally mixed into the reaction system For example, impurities contained in the raw material also destabilize the latex. When the latex becomes unstable, the latex particles aggregate and coalesce with each other, generating a large amount of scale, and sometimes causing a problem that the latex breaks down during the polymerization reaction and solids are separated and coagulated. . Furthermore, during the polymerization reaction, not all the monomers that remain unreacted in the latex are present inside the latex particles, and some exist as monomer droplets. When the latex becomes unstable, such as when the amount is insufficient, the ratio of the monomer present as monomer droplets increases, and as a result, a polymerization reaction occurs in the droplets, resulting in large scale. Problems arise. In addition, in a polymerization reaction system in which the viscosity of the latex is high, it is difficult to ensure sufficient stirring efficiency to sufficiently diffuse the added monomer, and the monomer is rapidly dispersed inside the latex particles. Can cause polymerization reaction in monomer droplets easily, and as a result, a large amount of monomer can be present in an unreacted state, destabilizing the latex and generating large amounts of scale This leads to problems such as

[0009] The scale generated is the inner wall of the polymerization machine or the stirrer.
If it adheres to a turbulence generating plate, etc., it takes time for washing and removal, and it floats in the latex and clogs pipes and filtration devices, which hinders stable production of the graft copolymer. Problems such as lower production efficiency.

[0010] In addition to the above, the generation of a large amount of scale adversely affects the quality of the obtained graft copolymer and a molded article using the graft copolymer. The polymerization reaction under conditions that easily generate scale is extremely unstable, and is easily affected by minute conditions such as changes in environmental conditions such as temperature and changes in impurities in raw materials and auxiliary materials. In addition, if scale adheres to the inner wall of the polymerization tank, the heat transfer state of the polymerization tank changes (generally, the scale is a polymer and the specific heat is low, so the heat transfer ability is reduced), so it is difficult to remove the generated heat of polymerization. And it may be difficult to control the temperature inside the polymerization tank. For these reasons, it is difficult to reproduce the polymerization reaction. In other words, the generation of such a scale is not a controlled reaction because it was not originally incorporated into the design intentionally for the production of the graft copolymer, and therefore, when a large amount of scale was generated, However, it is difficult for the obtained polymer to have the originally designed physical properties such as monomer residue composition and molecular weight, and the quality of the obtained graft copolymer varies. In addition, since the scale itself generated for the same reason is not suitable for use as a product, there is a problem that when a large amount of scale is generated, the product yield at the time of manufacturing is reduced and the production efficiency is reduced.

The problem that these scales occur in large quantities is that
It is known that the higher the solid content concentration in latex, the more likely it is to occur. Therefore, it is possible to reduce or avoid this problem by lowering the solid concentration in the latex. However, when the solid content concentration in the latex is reduced, the amount of raw materials that can be introduced into the reaction vessel is reduced, resulting in a problem that the production efficiency is reduced, and a step of isolating the obtained polymer from an aqueous medium. Also, various problems occur. For example, when a latex is spray-dried to isolate and recover a polymer, a lot of energy is required to volatilize and remove water, and after coagulation with an electrolyte or acid, it is separated and dried from an aqueous medium. In such a case, a large amount of aqueous medium must be removed, resulting in a problem such as an increase in the amount of wastewater, which leads to a decrease in production efficiency and an increase in environmental load.

As another method of suppressing the scale, a method of adding a surfactant or increasing the amount of the surfactant to be added during emulsion polymerization in order to prevent destabilization of the latex is effective. However, when a large amount of surfactant is used, a large amount of surfactant-derived impurities remain in the resulting polymer product, adversely affecting quality such as thermal stability, or increasing the concentration of waste liquid. Problems such as putting an environmental burden increase. In addition, in order to remove impurities to a sufficient degree, it is necessary to increase the degree of cleaning, which poses disadvantages in terms of manufacturing and the environment, such as requiring a long cleaning time and a large amount of cleaning water. Occurs. Furthermore, since a large amount of hydrophilic impurities derived from the surfactant easily remain, when the graft copolymer is separated from the aqueous medium, a large amount of water is retained in the graft copolymer, and as a result, time and energy are required for drying. It has been pointed out that the required or insufficient drying results in a large amount of non-volatile components remaining in the graft copolymer after isolation.

[0013] That is, it is difficult to achieve a balance between suppressing the generation of a large amount of scale and reducing the environmental load and improving the production efficiency, and a solution to this problem is strongly desired.

Until now, in order to suppress the amount of scale generation as much as possible, in the latter half when the solid content concentration in the latex is high, that is, in the polymerization reaction of a monomer or a monomer mixture having a composition giving a hard polymer. At this stage, many methods have been studied and developed in which the monomer or monomer mixture previously emulsified in an aqueous medium using a surfactant is supplied to a polymerization tank (Japanese Patent No. 2634691).
JP-A-5-262945, JP-A-5-262945
Japanese Patent No. 95050), although these methods have a certain effect in suppressing the amount of scale generation, it is hard to say that they have a sufficient effect, and the development of a method with higher effects is desired.

With respect to the production of crosslinked polymer fine particles having a simple structure, in order to suppress the scale and produce a stable polymer, a monomer or monomer mixture previously emulsified in an aqueous medium using a surfactant is used. A method for supplying the polymer to the polymerization tank has been studied and disclosed (JP-A-10-060016).
No.). However, the polymer fine particles that can be produced by this method are limited to the case where an alkyl methacrylate monomer having a simple structure and a glass transition temperature not so low is combined with an aromatic vinyl monomer. Even if the known technique is applied to produce a polymer having a multi-layered structure like a coalescence and containing a component having a low glass transition temperature such as a rubbery polymer, a sufficient effect cannot be obtained. This is presumably because the polymer having a low glass transition temperature easily swells in the monomer, and the generation of scale is particularly remarkable during the polymerization. Furthermore, the known technique uses an aromatic vinyl monomer as an essential component and utilizes its hydrophobicity, and there is a limit to the range of applicable monomer compositions, and it is widely used in the production of graft copolymers. Not available.

As described in detail above, when a graft copolymer is produced by an emulsion polymerization method, suppression of polymer scale and maintenance of stable quality, high production efficiency, stable production, and low environmental impact are simultaneously achieved. It can be said that the conventional technology has already reached its limit. And it is strongly desired to develop a new method for producing a graft copolymer that overcomes this limitation.

[0017]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing graft copolymer fine particles, which is highly stable in quality and at the same time enables high production efficiency and stable production.
It is still another object of the present invention to provide a method for producing a graft copolymer that reduces the environmental burden. Another object of the present invention is to provide a highly-quality stable graft copolymer produced by such a production method.

[0018]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have achieved the above-mentioned problems by adopting a specific manufacturing method in the production of graft copolymer fine particles. We have found what we can do and completed the present invention.

That is, the present invention provides a monomer having a composition that gives a rubbery polymer composed of at least one monomer in the presence or absence of particles (i) dispersed in an aqueous medium. Monomer mixture (iii) 70 having a composition giving a hard polymer composed of at least one kind of monomer after polymerization of 30 to 95 parts by weight of mixture (ii) in one or more stages.
-5 parts by weight ((ii) and (iii) 100 in total)
Parts by weight) of the monomer mixture (ii) in one or more stages to produce a multistage graft copolymer. The mixture (i) in contact with the activator
2. The method for producing a graft copolymer according to claim 1, wherein v) is supplied into a polymerization tank, and the mixed solution (iv) is a dispersion. The method for producing a graft copolymer according to claim 2, wherein the method for producing a graft copolymer (claim 2) comprises using a dispersion having a number average dispersed particle size of the dispersed phase of 300 μm or less. At least part or all of the monomer mixture (ii) is brought into continuous contact with the aqueous medium and the surfactant during the period from the storage of the monomer mixture (ii) to the polymerization tank until the monomer mixture (ii) is transferred to the polymerization tank. The method for producing a graft copolymer according to claim 2, wherein the prepared dispersion is supplied into a polymerization tank (claim 4), at least a monomer mixture (ii).
Is partially or entirely polymerized as a dispersion prepared by contacting with an aqueous medium and a surfactant in a storage facility for the monomer mixture (ii) or in a stirring tank for preparing the dispersion. The method for producing a graft copolymer according to claim 2, wherein the monomer mixture (ii) is polymerized in two or more stages.
3. The method for producing a graft copolymer according to claim 2, wherein at least 20% by weight of the total amount of the monomer mixture (ii) is used as a dispersion, and the monomer contained in the dispersion. The method for producing a graft copolymer according to claim 2, wherein the surfactant is used in an amount of 0.02 to 3 parts by weight and the aqueous medium is used in an amount of 8 to 200 parts by weight per 100 parts by weight of the mixture (ii). (Claim 7), a monomer mixture (ii)
At least one having an alkyl group having 2 to 12 carbon atoms
The method for producing a graft copolymer according to claim 1, wherein at least 55% by weight of a kind of alkyl acrylate monomer is used (claim 8), the monomer mixture (ii)
2. The method for producing a graft copolymer according to claim 1, wherein the polyfunctional monomer is used in an amount of 0.1 to 5% by weight (claim 9). 55% by weight or more of at least one alkyl acrylate monomer having at least 12 alkyl groups and 0.1% of the polyfunctional monomer.
The method for producing a graft copolymer according to claim 1, wherein the particles (i) dispersed in an aqueous medium are not used. The method for producing a graft copolymer according to claim 11, wherein the particles (i) dispersed in an aqueous medium are not more than 45% by weight of the total amount of the graft copolymer in solid content. The method for producing a graft copolymer according to claim 1, wherein polymer particles are used as the particles (i) dispersed in an aqueous medium. The production method (Claim 13),
At least one alkyl acrylate monomer having an alkyl group having 2 to 12 carbon atoms, at least one alkyl methacrylate monomer having an alkyl group having 1 to 12 carbon atoms, and an aromatic vinyl monomer A conjugated diene, a vinyl cyanide monomer, an acrylamide monomer, a methacrylamide monomer, at least one acrylic acid alkylamide monomer having an alkyl group having 1 to 16 carbon atoms, At least one having an alkyl group
2. A polymer comprising at least one monomer selected from the group consisting of methacrylic acid alkylamide monomers or a monomer mixture containing said monomers.
The method for producing a graft copolymer according to claim 12, wherein inorganic particles are used for the particles (i) dispersed in an aqueous medium (claim 14). (15) The method for producing a graft copolymer according to (12), wherein organic-inorganic composite particles are used as the particles (i) dispersed in the aqueous medium. The body mixture (iii) contains 1 to 12 carbon atoms
At least one alkyl methacrylate monomer having an alkyl group, at least one alkyl acrylate monomer having an alkyl group having 2 to 12 carbon atoms, an aromatic vinyl monomer, a vinyl cyanide monomer A monomer mixture containing at least one monomer selected from the group consisting of a monomer, a monoethylenically unsaturated carboxylic acid, a vinyl monomer containing an epoxy group, and a polyfunctional monomer. The method for producing a graft copolymer according to claim 1 (Claim 17), the graft copolymer produced by the method for producing a graft copolymer according to claim 1 (Claim 1)
8) having at least one shape selected from powder, granules, slurry, pellets and strands.
19. The graft copolymer according to claim 18, wherein the graft copolymer according to claim 19, the thermoplastic resin composition containing the graft copolymer according to claim 18 (claim 20), and 100 parts by weight of the thermoplastic resin. A thermoplastic resin composition containing the copolymer in an amount of 1 to 70 parts by weight (Claim 21), wherein the thermoplastic resin is vinyl chloride resin, chlorinated vinyl chloride resin, acrylic vinyl chloride resin, methyl methacrylate resin, acrylonitrile-styrene resin, 21. At least one resin or resin composition selected from the group consisting of methyl methacrylate-styrene resin, styrene resin, polycarbonate resin, polyester resin, polyether resin, and cycloolefin copolymer resin is used. The thermoplastic resin composition according to claim 22, wherein the thermoplastic resin is a vinyl chloride resin. The thermoplastic resin composition according to claim 20, wherein the composition contains at least 80% by weight or more (claim 23), and a molded article containing the thermoplastic resin composition according to claim 20 (claim 24). ) Is the content.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The monomer mixture (ii) used in the present invention and having a composition to give a rubbery polymer composed of at least one kind of monomer is partially or entirely composed of an aqueous medium and a surfactant. The mixture is supplied into the polymerization tank as a mixture (iv) brought into contact with the agent. Here, “contacted” means that a part or all of the monomer mixture, the aqueous medium, and the surfactant coexist. Specifically, the aqueous medium and the monomer mixture may be in a state of suspension, dispersion, emulsion or the like. Here, the surfactant may be previously mixed in the aqueous medium, or the monomer mixture, or both, or the monomer mixture and the aqueous medium may be mixed at the same time when the aqueous medium is allowed to coexist. Is also good. This allows the polymerization reaction to proceed stably even under conditions where the latex tends to be unstable. That is, in ordinary emulsion polymerization, it is possible to carry out polymerization in which scale is hardly generated by using a surfactant in an amount smaller than the surfactant amount necessary for maintaining the stability of the latex. At this time, a remarkably high effect is obtained when a so-called dispersion liquid in which the aqueous medium and the monomer or the monomer mixture are not visually separated is used as the mixed liquid (iv). Furthermore, more preferably, 0.02 to 20
The highest effect is obtained when a dispersion having a thickness of 0 μm, particularly preferably 0.05 to 150 μm, is used. 300μ
The effect of the present invention can be obtained even when the thickness exceeds 300 μm. However, when the thickness is 300 μm or less, the effect of suppressing the generation of scale is excellent and suitable. The method for measuring the number average dispersed particle diameter will be described in detail in Examples below.

The dispersion used in the present invention can be easily prepared, particularly, in a storage facility for the monomer mixture (ii) or in a stirring tank for preparing the dispersion. However, when the dispersion is kept for a long time in such a storage facility, the monomer mixture (ii) may be separated from the aqueous medium. Further, depending on the type of the monomer, or when the polymerization initiator is kept in the storage facility or the like in a state of being mixed with the dispersion liquid, or by the incorporation of an uncontrollable impurity even in a small amount (substantially, In the production process of chemical products, the possibility of contamination by a trace amount of impurities is not always zero), and the polymerization reaction may proceed in such storage facilities. Therefore, it is preferable to supply the dispersion immediately after the preparation into the polymerization tank. In these respects, the step of preparing the dispersion, which is performed in advance before supplying the mixture to the polymerization tank, that is, the step of bringing at least a part or all of the monomer mixture (ii) into contact with the aqueous medium and the surfactant,
It is particularly preferred that the monomer mixture (ii) be continuously carried out during the transfer step until part or all of the monomer mixture (ii) is supplied from the storage facility into the polymerization tank. Specific examples of such equipment include an in-line mixer installed in the middle of the transfer step, and an equipment equipped with a pipeline homomixer. The in-line mixer refers to a transfer / mixing equipment equipped with a screw or a stirring device or a turbulence generating device for mixing and stirring in a pipe. Pipeline homomixer is installed in the middle of piping,
The monomer mixture (i
This refers to a transfer and mixing facility in which a mixture of i), an aqueous medium and a surfactant is sheared to form a fine dispersion or emulsion.

The polymerization of the monomer mixture (ii) may be performed in only one stage, or may be performed in two or more stages.
When the composition is divided into two or more stages, the monomer composition in each stage may be the same or different. Also,
When divided into two or more stages, the monomer mixture (i
It is most preferable to supply all of i) as a dispersion to the polymerization tank, but this is not always necessary, and the amount of the monomer mixture (ii) to be supplied to the polymerization tank as a dispersion is limited to the monomer mixture (ii). If it becomes 20% by weight or more of the total amount of
The monomer mixture (ii) may be supplied in any manner. That is, when the polymerization of the monomer mixture (ii) is performed in two or more stages, the preferable amount of the monomer mixture (ii) to be supplied as a dispersion to the polymerization tank is determined by the monomer mixture (ii) to be supplied. 20 to 100% by weight, more preferably 30 to 100% by weight, particularly preferably 50 to 100% by weight of the total amount of
100% by weight. If it is less than 20% by weight, the effect of suppressing scale is insufficient, which is not preferable.

The monomer mixture (i) contained only in the dispersion
When the total amount of i) is 100 parts by weight, the amount of the surfactant used for preparing the dispersion is preferably 0.02 to 3 parts by weight, more preferably 0.1 to 2 parts by weight. On the other hand, the amount of the aqueous medium is preferably from 8 to 200 parts by weight, more preferably from 10 to 50 parts by weight. Depending on the particle size of the graft copolymer, if the amount of the surfactant exceeds 3 parts by weight, new particles (undesigned particles generated due to excess surfactant during continuous emulsion polymerization) may be generated. , It becomes difficult to produce a graft copolymer with stable quality, and the environmental load of wastewater generated when the graft copolymer is isolated increases, and furthermore, the amount of impurities remaining in the graft copolymer is reduced. More. Conversely, when the amount is less than 0.02 parts by weight, scale is easily generated, and it becomes difficult to produce a graft copolymer with stable quality, which is not good. If the amount of the aqueous medium is less than 8 parts by weight, mixing tends to be inappropriate, or the degree of mixing is reduced and the scale tends to increase, that is, it becomes difficult to obtain a graft copolymer of stable quality, If the amount is more than 200 parts by weight, the final solid content of the graft copolymer latex is low, resulting in a decrease in production efficiency and an increase in the amount of waste water at the time of isolation of the graft copolymer.

The monomer mixture (ii) has a composition that gives a rubber-like polymer composed of at least one kind of monomer, is capable of emulsion polymerization, and has a composition that gives a rubber-like polymer. Although there is no particular limitation,
It is preferable to use one containing 55% by weight or more of at least one alkyl acrylate monomer having 12 alkyl groups, and more preferably one containing 70 to 99.9% by weight. The amount of the alkyl acrylate monomer used is determined by the monomer mixture (i
It may be 100% by weight corresponding to the total amount of i), but if it is less than 55% by weight, the glass transition temperature of the rubbery polymer becomes high and the modulus of elasticity becomes too large. The impact strength of the molded article tends to decrease, and is not suitable for the use of the graft copolymer produced according to the present invention. It is preferable to use 0.1 to 5% by weight of a polyfunctional monomer in the monomer mixture (ii) since a good rubbery polymer can be obtained, and 0.3 to 2.5% by weight. If used, more favorable results are obtained. The polyfunctional monomer acts as a cross-linking point for chemically cross-linking the molecular chain of the rubber-like polymer, but if the number of cross-linking points is too large, the elastic modulus of the rubber-like polymer becomes too high. The impact strength of the resin molded article obtained from the union decreases. for that reason,
The upper limit of the amount of the polyfunctional monomer used is preferably 5% by weight.
And more preferably 2.5% by weight. When the amount of the polyfunctional monomer used is reduced, the number of crosslinking points decreases, and the amount of the rubbery polymer component effective because the molecular chain becomes difficult to form a network structure decreases. There is a tendency that the impact strength of the obtained resin molded article is reduced.
However, when the molecular weight is sufficiently large even if there is no chemical cross-linking point in the molecular chain, that is, when the molecular chain is sufficiently long, the entanglement point between the entangled molecular chains acts as a physical cross-linking point, so that the rubber-like weight is increased. It can exhibit a function as coalescence. However, in order to obtain a sufficient amount of an effective rubbery polymer component, it is not necessary to use a polyfunctional monomer, but the lower limit of the amount is preferably 0.1% by weight.
It is. The use amount of the alkyl acrylate is 5
5% by weight or more, and the polyfunctional monomer is added in an amount of 0.1%.
By using 5 to 5% by weight, the most preferable rubbery polymer can be efficiently obtained, and the impact strength of the molded article obtained from the graft copolymer is also improved most.

Examples of the alkyl acrylate monomer used in the monomer mixture (ii) include ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and the like. It is not limited. Examples of the polyfunctional monomer used in the monomer mixture (ii) include divinylbenzene, ethylene glycol dimethacrylate, diallyl phthalate,
Examples thereof include, but are not limited to, divinyl monomers and trivinyl monomers such as allyl acrylate, allyl methacrylate, and trimethylolpropane trimethacrylate. In the monomer mixture (ii), other copolymerizable vinyl monomers such as an alkyl methacrylate monomer, an aromatic vinyl monomer, and a vinyl cyanide monomer are further used as a copolymerization component. May be used. Examples of the alkyl methacrylate monomer include methyl methacrylate and n-methacrylic acid.
-Butyl, 2-ethylhexyl methacrylate, dodecyl methacrylate, and the like. Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, p-methylstyrene, halogenated styrene, 2-vinylnaphthalene,
Examples of vinyl cyanide monomers such as vinyl anthracene and the like include, but are not limited to, acrylonitrile, methacrylonitrile and the like. Also, other copolymerizable vinyl monomers include:
For example, substituted (meth) acrylates such as 4-hydroxybutyl acrylate and vinyl esters such as vinyl propionate can be used.

Examples of the polymerization initiator used for the polymerization of the monomer mixture (ii) include peroxides of ketone or aldehyde such as cyclohexanone peroxide, diacyl peroxides such as acetyl peroxide, t-butyl hydroperoxide, Hydroperoxides such as cumene hydroperoxide, dialkyl peroxides such as di-t-butyl peroxide, t-
Organic peroxides such as alkyl peresters such as butyl perisobutylate; percarbonates such as t-butyl peroxyisopropyl carbonate; inorganic peroxides such as hydrogen peroxide and potassium persulfate; Examples include, but are not limited to, azo compounds such as' -azobisisobutyronitrile. When organic peroxides and / or inorganic peroxides are used, these may be used as a thermal decomposition type polymerization initiator, and a reducing agent such as sodium ascorbate and sodium formaldehyde sulfoxylate may be used. Depending on the conditions, a co-catalyst such as ferrous sulfate and a chelating agent such as ethylenediaminetetraacetate may be used in combination as a redox-type polymerization initiator. These monomer mixtures (ii)
The polymerization initiator used for the polymerization may be previously charged in the polymerization tank, may be directly supplied to the polymerization tank during or after the supply of the monomer mixture (ii), or may be supplied to the polymerization tank. The monomer mixture (ii) or a mixture of the monomer mixture (ii) with an aqueous medium and a surfactant (i
v) may be mixed. It is also possible to combine a plurality of these means.

The aqueous medium referred to in the present invention is 90% by weight of water.
A liquid containing the above and having a composition capable of emulsion polymerization in the aqueous medium. The aqueous medium may contain up to 10% by weight of a liquid other than water that can be mixed with water as long as emulsion polymerization is possible in the aqueous medium. Here, liquids other than water that can be mixed with water include acetone, methyl alcohol, ethyl alcohol, propyl alcohol,
Examples include, but are not limited to, butyl alcohol, tetrahydrofuran, dimethylformaldehyde, and the like.

The type of the surfactant used in the present invention is not particularly limited, and may be an anionic surfactant, a nonionic surfactant, a cationic surfactant, or an anionic surfactant. Any of a combination of a nonionic surfactant and a combination of a cationic surfactant and a nonionic surfactant may be used. Examples of the anionic surfactant include, but are not particularly limited to, alkali metal salts of fatty acids such as potassium palmitate, sodium oleate, and sodium stearate, sodium dodecyl sulfate, triethanolamine dodecyl sulfate, and ammonium dodecyl sulfate. Alkali metal salts or amine or ammonium salts of higher alcohol sulfates represented by, for example, sodium dodecylbenzenesulfonate, alkali metal salts of alkylbenzenesulfonic acid or alkylnaphthalenesulfonic acid represented by sodium dodecylnaphthalenesulfonate, naphthalenesulfonic acid Alkali metal salts such as sodium salt of formalin condensate, alkali metal salts such as sodium salt of dialkyl sulfosuccinic acid, alkyl phosphate Which alkyl phosphate salts, polyoxyethylene alkyl ether sulfate, polyoxyethylene sulfate salts such as polyoxyethylene alkyl phenyl ether sodium sulfate. Examples of the nonionic surfactant include, but are not limited to, polyoxyethylene alkyl ethers such as polyoxyethylene dodecyl ether and polyoxyethylene stearyl ether, and polyoxyethylene alkyl phenols such as polyoxyethylene nonyl phenol ether. Ethers, sorbitan monostearate, sorbitan distearate, sorbitan fatty acid esters such as sorbitan sesquioleate,
Polyoxyethylene sorbitan fatty acid esters represented by polyoxyethylene sorbitan monostearate, polyoxyethylene acyl esters such as polyethylene glycol monostearate and polyethylene glycol distearate, and oxyethylene oxypropylene block polymers (molecular weight of about 2000 to about 1000
0) and fatty acid monoglycerides such as glyceryl monooleate. Examples of the cationic surfactant include, but are not particularly limited to, alkylamine salts such as dodecylamine acetate, quaternary ammonium salts such as dodecyltrimethylammonium chloride, and polyoxyethylene alkylamine. Can be In addition to these, it is also possible to use a polymer surfactant.

The total amount of the monomer mixture (ii) is 30 to 9 per 100 parts by weight of the finally obtained graft copolymer.
5 parts by weight, preferably 40 to 90 parts by weight, more preferably 50 to 87 parts by weight. If the amount is less than 30 parts by weight, the impact strength of the resin molded article obtained from the graft copolymer is lowered, which is not preferable. If the amount is more than 95 parts by weight, the graft portion of the graft copolymer covers the rubber-like polymer well. However, the graft copolymer cannot be dispersed well in the resin molded product, so that the impact strength of the resin molded product is lowered.

The glass transition temperature (Tg) of the rubbery polymer obtained by polymerizing the monomer mixture (ii) is preferably 0 ° C. or lower, more preferably -20 ° C. or lower. In the present invention, when a monomer mixture (ii) having such a composition is used, a good rubbery polymer having a particularly low elastic modulus can be formed, and a resin obtained from a graft copolymer can be formed. Particularly good impact strength of the molded body can be achieved.

In the present invention, without using the particles (i) dispersed in an aqueous medium, a monomer mixture (ii) having a composition to give a rubbery polymer composed of at least one monomer is used. The polymerization may be started. At this time, the polymerization may be started by continuous emulsion polymerization of part or all of the monomer mixture (ii), but the monomer mixture (i)
The polymerization of i) is divided into two or more stages, and the first stage which is a part of the monomer mixture (ii) is subjected to a seed emulsion polymerization method (a predetermined amount of monomer or monomer charged in a polymerization tank). The mixture is first dispersed in an aqueous medium using a surfactant,
A method in which a polymer latex is obtained by polymerizing monomers in a polymerization tank, and the obtained polymer particles function as seeds in the subsequent polymerization.), Suspension polymerization, miniemulsion polymerization Polymerization may be carried out using a synthesizing method or a microemulsion polymerization method.

When the particles (i) dispersed in an aqueous medium are used, the amount of the particles (i) used is preferably in the range of 0 to 45% by weight of the total amount of the graft copolymer in terms of solid content, more preferably. Is 3 to 35% by weight. By suppressing the use amount of the particles to 45% by weight or less, the rubber-like polymer satisfactorily coats the periphery of the particles, so that the impact resistance improving function is not impaired, and the affinity with the matrix resin is good. Since it is possible to satisfactorily coat the periphery of the rubber-like polymer with the hard polymer having, it is possible to maintain a good dispersion state of the graft copolymer in the matrix resin,
It is possible to prevent the impact resistance improving function from being deteriorated due to poor dispersion.

As the particles (i) to be dispersed in the aqueous medium used in the present invention, polymer particles can be used. Polymer particles include polymer particles stably dispersed in an aqueous medium using a surfactant (that is, latex), polymer particles having a hydrophilic group on or near the surface, or a polymer stabilizer. It may be a polymer particle or the like stably dispersed in an aqueous medium, but is not limited thereto. The composition of the monomer which gives the polymer contained in the polymer particles is not particularly limited, but at least one alkyl acrylate monomer having an alkyl group having 2 to 12 carbon atoms, At least one alkyl methacrylate monomer having an alkyl group of Formulas 1 to 12, aromatic vinyl monomer, conjugated diene, vinyl cyanide monomer, acrylamide monomer, methacrylamide monomer, carbon At least one selected from the group consisting of at least one alkyl amide monomer having an alkyl group having 1 to 16 carbon atoms and at least one alkyl amide monomer having at least one alkyl group having 1 to 16 carbon atoms. It is preferred to use a species monomer or a monomer mixture containing said monomer. Here, the same alkyl acrylate monomer, alkyl methacrylate monomer, aromatic vinyl monomer, and vinyl cyanide monomer as those in the monomer mixture (ii) can be exemplified.
It is not limited to these. Further, the conjugated diene includes at least one having an alkyl group having 1 to 16 carbon atoms such as butadiene, isoprene and chloroprene.
Kinds of acrylic acid alkylamide monomers include, for example, dodecyl acrylamide and cyclododecylacrylamide, and at least one methacrylic acid alkylamide monomer having an alkyl group having 1 to 16 carbon atoms includes, for example, dodecyl methacrylamide. Examples include, but are not limited to, cyclododecyl methacrylamide, octyl methacrylamide, adamantyl methacrylamide, and the like. Further, a monomer containing a silicon atom as a monomer to give a polymer contained in the polymer particles, or a monomer mixture comprising a monomer containing a silicon atom and a monomer copolymerizable therewith. It can also be used. Here, the monomer containing a silicon atom includes, for example, a tetramer of dimethylsiloxane, but is not limited thereto.

As the particles (i) dispersed in the aqueous medium used in the present invention, inorganic particles can also be used. As the inorganic particles, for example, calcium carbonate, titanium dioxide,
Examples include, but are not limited to, fine particles of a poorly water-soluble or water-insoluble inorganic compound such as zeolite, silica, and mica. The size and shape of these inorganic particles are not particularly limited. Further, the particles (i) dispersed in the aqueous medium used in the present invention include organic-
Inorganic composite particles can be used. Also in this regard, there is no particular limitation on the composition, size and shape. When the inorganic particles or the organic-inorganic composite particles are used as the particles (i) dispersed in an aqueous medium, a special function based on the inorganic compound can be imparted to the graft copolymer. For example, when the inorganic compound is zeolite, a function of suppressing harmful substances generated during incineration can be imparted to the graft copolymer.

In the polymerization of the monomer mixture (iii) having a composition to give a hard polymer comprising at least one monomer used in the present invention, the monomer mixture (iii)
The polymerization of i) may be performed in one stage, or may be performed in two or more stages. When the polymerization is carried out in two or more stages, the composition of the monomer mixture (iii) in each stage may be the same or different. The monomer mixture (iii) is generally supplied to the polymerization tank without being mixed with the aqueous medium and the surfactant. It is also possible to supply a mixed solution, preferably a dispersion, to the polymerization tank in contact with the surfactant. Polymerization of monomer mixture (iii)
In the case of performing the treatment in stages or more, those methods can be used in combination. Before supplying part or all of the monomer mixture (iii) to the polymerization tank, the aqueous medium and the surfactant used when previously contacting the aqueous medium and the surfactant to form a mixed solution or a dispersion, The same as that used for the polymerization of the monomer mixture (ii) is not limited thereto, and need not be the same as that used for the polymerization of the monomer mixture (ii). The method of contacting an aqueous medium and a surfactant in advance to form a mixture or dispersion before a part or all of the monomer mixture (iii) is supplied to the polymerization tank is not particularly limited, but may be a single monomer. The same method as described in the polymerization of the body mixture (ii) can be exemplified.

The monomer mixture (iii) is not particularly limited as long as it is capable of emulsion polymerization.
In particular, at least one alkyl methacrylate monomer having an alkyl group having 1 to 12 carbon atoms, at least one alkyl acrylate monomer having an alkyl group having 2 to 12 carbon atoms, aromatic vinyl monomer Monomer containing at least one monomer selected from the group consisting of monomer, vinyl cyanide monomer, monoethylenically unsaturated carboxylic acid, epoxy group-containing vinyl monomer and polyfunctional monomer By using the mixture, it is possible to achieve appropriate adhesion to the interface between the graft copolymer and the resin matrix in the resin molded product obtained from the graft copolymer, and the graft copolymer is well dispersed in the resin matrix. Good impact strength of the resin molded article can be achieved. The above-mentioned alkyl acrylate monomer, alkyl methacrylate monomer, aromatic vinyl monomer, vinyl cyanide monomer, and polyfunctional monomer are exemplified for the monomer mixture (ii). However, the present invention is not limited to these. Further, examples of the monoethylenically unsaturated carboxylic acid include acrylic acid and methacrylic acid, and examples of the epoxy group-containing vinyl monomer include glycidyl methacrylate and the like, but are not limited thereto. Not something.

The glass transition temperature (Tg) of the polymer obtained by homopolymerizing the monomer mixture (iii) is 20 ° C.
As described above, the temperature is preferably 40 to 130 ° C, more preferably 50 to 110 ° C. By using the monomer mixture (iii) having such a composition, heat blocking and heat fusion of the graft copolymer can be suppressed, and the isolated graft copolymer is kept at room temperature. It becomes easy to save.

The total amount of the monomer mixture (iii) is 70 to 100 parts by weight per 100 parts by weight of the finally obtained graft copolymer.
5 parts by weight, preferably 60 to 10 parts by weight, more preferably 50 to 13 parts by weight. If the amount is more than 70 parts by weight, the impact strength of the resin molded article obtained from the graft copolymer decreases, so that it is not preferable. If it is less than 5 parts by weight, the graft copolymer obtained by polymerizing the monomer mixture (iii) Cannot sufficiently cover the rubber-like polymer, and as a result, the graft copolymer cannot be dispersed well in the resin molded article, which undesirably lowers the impact strength of the resin molded article. The total amount of the monomer mixture (ii) and the monomer mixture (iii) is 100 parts by weight.

The polymerization initiator used for the polymerization of the monomer mixture (iii) is the same as, but not limited to, the one used for the polymerization of the monomer mixture (ii). It need not be the same as that used for the polymerization of (ii). The method of using the polymerization initiator in the polymerization of the monomer mixture (iii) is the same as in the polymerization of the monomer mixture (ii).

The graft copolymer obtained by the production method of the present invention described above has a stable composition and molecular weight because it hardly involves a polymerization scale, and as a result, its quality is stable. When compounded with a resin to form a resin molded article, it can be used as a good impact resistance improver that stably exhibits its quality. Furthermore, the graft copolymer produced by the production method of the present invention is produced by using a small amount of a surfactant, compared to the graft copolymer produced by the production method not by the production method of the present invention. It has a small amount of residual surfactant as an impurity and is suitable for use as an impact resistance improver that does not impair the thermal stability of the resin molded product.

The graft copolymer obtained by the production method of the present invention is isolated from a latex by a known method such as spray drying, gas phase coagulation, salting out coagulation, acid coagulation or freeze coagulation, and then is isolated from powder. It can be at least one shape selected from a body, a granule, a slurry, a pellet, and a strand.

The graft copolymer is used in an amount of 1 to 70 parts by weight, preferably 3 to 70 parts by weight, based on 100 parts by weight of the thermoplastic resin composition containing the graft copolymer.
A thermoplastic resin composition containing 30 parts by weight, more preferably 4 to 18 parts by weight, has excellent impact resistance, good thermal stability, is hardly colored by heat, and can produce a resin molded article of very stable quality. Suitable as a well-fed material. The thermoplastic resin composition is, in particular, vinyl chloride resin, chlorinated vinyl chloride resin, acrylic vinyl chloride resin, methyl methacrylate resin, acrylonitrile-styrene resin, methyl methacrylate-styrene resin, styrene resin, polycarbonate resin, polyester resin, polyether Resin, when it contains at least one resin or resin composition selected from the group consisting of cycloolefin copolymer resins, it is excellent as a material that gives a good molded product, and the thermoplastic resin is at least a vinyl chloride resin. When the content is 80% by weight or more, it is a material that gives a particularly excellent molded product. Fillers, stabilizers, lubricants, plasticizers, coloring agents, foaming agents, and the like may be added to these thermoplastic resin compositions according to the purpose.

A resin molded article obtained by molding these thermoplastic resin compositions and containing the thermoplastic resin composition containing the above graft copolymer has excellent impact resistance and good thermal stability. In addition, it is a molded product that is difficult to heat-color and has good reproducibility of quality.

[0044]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited thereto. Parts represent parts by weight. Abbreviations of compounds used in Examples, Comparative Examples and Tables are as follows.

2EHA: 2-ethylhexyl acrylate ALMA: allyl methacrylate BA: butyl acrylate BMA: butyl methacrylate Ma: methacrylic acid MMA: methyl methacrylate St: styrene PMMA: polymethyl methacrylate CaCO ₃ : calcium carbonate TiO ₂ :titanium dioxide

Evaluations in the examples and comparative examples were made according to the following methods.

(1) Identification of Dispersion Phase of Dispersion or Emulsion Containing Monomer, Aqueous Medium and Surfactant A mixture of the monomer, the aqueous medium and the surfactant was prepared on a preparation (glass plate). One drop was dropped, and the magnification was fixed at a magnification at which 10 or more dispersed phase particles could be observed within the observation visual field range with an optical microscope (manufactured by Hi-Rox Corporation). The number of dispersed phase particles observable in the observation visual field range was counted, and at the same time, the approximate particle size of the dispersed phase particles was estimated. Thereafter, 5 drops of pure water are added to the mixture on the preparation, and observation is performed at the same magnification as before, and the number of dispersed phase particles that can be observed in the observation visual field is counted again. Estimated. When the approximate particle size of the dispersed particles does not change much before and after the addition of pure water, and when the number of dispersed particles that can be observed in the observation visual field decreases by a significant number after the addition of pure water, the main component of the dispersed phase is It was a monomer and the main component of the continuous phase was determined to be an aqueous medium. After the addition of pure water, the monomer and the aqueous medium are separated, or when the particle size of the observed dispersed particles is significantly increased, the main component of the dispersed phase is an aqueous medium,
The main component of the continuous phase was determined to be a monomer.

(2) Measurement of Number Average Dispersion Particle Size of Disperse Phase of Dispersion or Emulsion Containing Monomer, Aqueous Medium and Surfactant Mixing of Monomer, Aqueous Medium and Surfactant on Prepare One drop of the solution is dropped, and 1
The magnification was fixed at a magnification at which 0 or more dispersed phase particles could be observed. The number of all dispersed phase particles observable in the observation visual field range was counted, and the particle diameter of each particle was estimated. The number average dispersed particle diameter (μm) of the dispersed phase was determined based on the obtained results.

(3) Amount of Scale Generated After the polymerization, all the scales adhered to the polymerization tank and the stirrer and the scales suspended in the latex were collected and washed with water, and the dry weight was determined. The weight was expressed in% as "scale generation amount" with respect to the total weight of the monomer mixture charged in the polymerization tank.

(4) Measurement of COD in drainage 100 g of a latex containing a graft copolymer was weighed based on the weight of the graft copolymer, 300 g of water was added thereto, and the mixture was coagulated with 5 parts by weight of calcium chloride. After heating and holding for 5 minutes, the mixture was filtered and dehydrated, and the waste water was collected. Further, 300 g of water was added to the graft copolymer on the filter paper.
Water washing, filtration, and dewatering were performed, and the wastewater was combined with the previous wastewater. The COD (chemical oxygen demand) of the obtained wastewater was measured (ppm) with a simple measuring device (manufactured by Central Chemical Co., Ltd.).

(5) Residual Impurity Measurement 1 g of the graft copolymer obtained at the time of wastewater COD measurement was dried.
Weigh, add 20 g of methyl ethyl ketone, and add
Allowed to swell for time. The soluble and insoluble components in methyl ethyl ketone were separated by centrifugation.
Was dropped. The reprecipitated insolubles were separated by filtration, the filtrate was dried, and the obtained solid was recovered. This was regarded as a residual impurity, the weight was measured, and the weight fraction (%) based on the graft copolymer was determined.

(6) Quality Stability of Graft Copolymer In the measurement of the amount of residual impurities, the insoluble matter filtered off after reprecipitation from methanol was dried, and this was defined as the weight of by-product free polymer (hereinafter referred to as FP). Five graft copolymer samples having the same contents were prepared for each of the examples and comparative examples, and the FP ratio was determined for each, to obtain the maximum and minimum values. The maximum value and the minimum value, that is, the range of the FP ratio was used as an index of the quality stability of the graft copolymer in each of the examples and comparative examples (the smaller the range, the more stable it is judged).

(7) Impact Strength A predetermined number of the graft copolymer was prepared by adding 2 parts of tribasic lead sulfate,
2 parts of dibasic lead phosphite, 0.2 parts of dibasic lead stearate.
5 parts and 90 parts of a vinyl chloride resin (average degree of polymerization: 1000) containing 0.5 part of calcium stearate were mixed to prepare a vinyl chloride resin composition. These vinyl chloride-based resin compositions were connected to a Labo Plast Mill (manufactured by Toyo Seiki Co., Ltd.) using a small bi-directional twin screw extruder with a width of 7 cm.
It was extruded at 180 to 185 ° C into a sheet having a thickness of 3 mm. The extruded product was cut so as to have a notch in the direction perpendicular to the flow direction of the extruder, thereby preparing 10 Charpy test pieces (test piece type 1 (length 8 cm × width 1 cm, thickness 3 mm)). , Single notch A (R = 0.25m
m)), and Charpy strength was evaluated (JIS K-71).
11). The evaluation was performed for each example or comparative example.

(8) Thermal stability The same extruded sheet as that produced in the impact test was used for
A test piece having a size of 0 cm × 5 cm × thickness 3 mm was cut, heated in an oven at 100 ° C. × 3 hours, allowed to cool to room temperature, and visually evaluated for the degree of discoloration. The evaluation was performed in five stages, and was rated from 5 (no discoloration) to 1 (large discoloration).

Example 1 (I) Preparation of rubbery polymer: Pure water 13 was placed in a reactor equipped with a stirrer.
5 parts (When the amount of water at the time of
Part. The same applies to Examples 2 to 13 and Comparative Examples 1 to 5 described later), 0.3 parts of sodium oleate, 0.2 parts of sodium naphthalene sulfonate.
Parts, ferrous _{(FeSO 4 · 7H 2 O)} 0.005 parts of sulfuric acid,
Ethylenediaminetetraacetic acid.2Na salt 0.01 part, sodium formaldehyde sulfoxylate 0.2 part, sodium phosphate decahydrate 0.5 part were charged, and the inside of the reactor was replaced with nitrogen to replace the space part and the water part. After removing oxygen, the content was heated to 50 ° C. while stirring. In addition, 79.6 butyl acrylate containing 0.05 parts of cumene hydroperoxide prepared in advance.
Part of a monomer mixture of 0.4 parts of allyl methacrylate and an aqueous sodium oleate solution obtained by dissolving 0.6 part of sodium oleate in 15 parts of pure water for 4 hours using a pipeline homomixer (operated at 3600 rpm). Model 125
L (manufactured by Dimension Corporation)) while continuously mixing and emulsifying the mixture, and then supplying the mixture to the reactor. A part of the emulsion was sampled and evaluated (1) and (2). The results are shown in Tables 1 and 2. Stir for 1 while keeping the contents at 50 ° C.
The polymerization was completed for more than an hour to obtain a rubbery polymer latex.

(II) Polymerization of graft portion: After adding 0.02 part of potassium persulfate to the composite latex, a monomer mixture of 15 parts of methyl methacrylate and 5 parts of butyl methacrylate was added for 1 hour. Added continuously. At the end of the addition of the monomer mixture, further add 0.02 parts of potassium persulfate.
Stirring was continued for 1 hour or more while keeping the content at 50 ° C. to complete the polymerization, and a graft copolymer latex having a latex particle diameter of 120 nm was obtained. Evaluations (3) to (6) were performed using a part of the graft copolymer latex. Table 3 shows the results.

(III) 5 parts of calcium chloride was added to the obtained graft copolymer latex to carry out salting out and coagulation.
After heating to 80 ° C., dehydration, washing and drying, a white powdery graft copolymer having an average particle size of about 80 μm was obtained.

(IV) Evaluations (7) and (8) were performed using the obtained powdery graft copolymer (10 parts of the graft copolymer was used for 90 parts of vinyl chloride resin). . Table 3 shows the results.

Examples 2 and 3 In (I), except that an aqueous sodium oleate solution prepared from sodium oleate and pure water in the amounts shown in Tables 1 and 2 was used for emulsification of the monomer mixture. Example 1
The same as above. The results are shown in Tables 1, 2 and 3.

Example 4 In (I), 146 parts of initial pure water was used, and an aqueous solution of sodium oleate (0.6 part of sodium oleate / 4 parts of pure water) was used for contact and mixing with the monomer mixture. Example 2 was the same as Example 1 except that was used. The results are shown in Tables 1, 2 and 3.

Example 5 In (I), the monomer mixture liquid and the sodium oleate aqueous solution were simply connected before the monomer mixture liquid and the sodium oleate aqueous solution were supplied to the reactor. The procedure was the same as in Example 1 except that the reactor was connected to the reactor and the mixture was continuously supplied to the reactor over 4 hours. The results are shown in Tables 1, 2 and 3.

Example 6 In (I), an aqueous solution of sodium oleate was charged into a container containing a monomer mixture, stirred, and emulsified.
Example 1 was repeated except that the emulsion was continuously supplied to the reactor over 4 hours while maintaining the stirring in the vessel. The results are shown in Tables 1, 2 and 3.

Example 7 In (I), 5 parts of the monomer mixture was continuously mixed with 6.25% by weight of a sodium oleate aqueous solution for monomer emulsification via a pipeline homomixer. The mixture was emulsified and supplied to the reactor over 15 minutes. Subsequently, the residue of the monomer was continuously supplied to the reactor over 3 hours and 45 minutes. Example 1 was the same as Example 1 except that the addition was performed in three equal portions 1, 2, and 3 hours after the addition was started. The results are shown in Tables 1, 2 and 3.

Example 8 In (I), 20 parts of the monomer mixture was continuously mixed and emulsified with 25% by weight of an aqueous sodium oleate solution for monomer emulsification via a pipeline homomixer. To the reactor over 1 hour, and then continuously supply the monomer residue to the reactor over 3 hours. The sodium oleate aqueous solution residue starts to be added to the monomer residue. From 1
Example 1 except that the mixture was added in two equal portions after 2 hours and
The same as above. The results are shown in Tables 1, 2 and 3.

Examples 9 to 12 The same procedures as in Example 1 were carried out except that a monomer mixture having the contents shown in Tables 1 and 2 was used. The results are shown in Tables 1, 2 and 3.

Example 13 Example 13 was the same as Example 1 except that a monomer mixture for graft polymerization having the compositions shown in Tables 1 and 2 was used. The results are shown in Tables 1, 2 and 3.

Comparative Examples 1 to 3 In (I), only the monomer mixture was continuously supplied to the reactor over 4 hours, and an aqueous sodium oleate solution (amount of sodium oleate / amount shown in Tables 1 and 2) was used. Example 15 was the same as Example 1 except that pure water (15 parts) was added in three equal portions every hour during the addition of the monomer mixture. The results are shown in Tables 1, 2 and 3.

Comparative Example 4 In (I), 145 parts of initial pure water were used, 4.975 parts of butyl acrylate containing 0.003 parts of cumene hydroperoxide and 0.025 parts of allyl methacrylate were used.
Parts of the monomer mixture and an aqueous solution of sodium oleate obtained by dissolving 0.6 parts of sodium oleate in 5 parts of pure water, and continuously supplied to the reactor over 15 minutes, and (II) , After adding 0.02 parts of potassium persulfate, continuously adding a monomer mixture of 71.25 parts of methyl methacrylate and 23.75 parts of butyl methacrylate over 4 hours and 45 minutes; Example 1 was repeated except that 0.02 parts of potassium persulfate was added every hour after the start of the supply. The results are shown in Tables 1, 2 and 3.

Comparative Example 5 In (I), 130 parts of the initial pure water was used, and 99.5 parts of butyl acrylate containing 0.063 parts of cumene hydroperoxide and 0.5 part of allyl methacrylate were used in a single amount. Using a body mixture and an aqueous solution of sodium oleate obtained by dissolving 0.6 part of sodium oleate in 20 parts of pure water, continuously feeding the reactor over 5 hours (I
Example 1 was the same as Example 1 except that the polymerization of the graft portion in I) was not performed. The results are shown in Tables 1, 2 and 3.

[0070]

[Table 1]

[0071]

[Table 2]

[0072]

[Table 3]

Example 14 (I) Preparation of poly (methyl methacrylate) polymer latex: 260 parts of pure water was charged into a reactor equipped with a stirrer (the amount of water at the end of the polymerization of the poly (methyl methacrylate) polymer was 280 parts). ), Sodium oleate 0.3 part, sodium naphthalene sulfonate 0.4 part, ferrous sulfate (FeSO ₄
・ 7H ₂ O), 0.01 part of ethylenediaminetetraacetylic acid ・ 0.02 part of 2Na salt, 0.4 part of sodium formaldehyde sulfoxylate, 1 part of sodium phosphate dodecahydrate, and nitrogen in the reactor After replacement to remove oxygen in the space and water, the contents were heated to 50 ° C. while stirring. To this, a monomer mixture of 192 parts of methyl methacrylate containing 0.3 part of cumene hydroperoxide and 8 parts of allyl methacrylate was continuously added over 10 hours. On the way, an aqueous solution of sodium oleate (0.2 part of sodium oleate / 20 parts of pure water) was added to the reactor in four portions every two hours. 50 contents
The stirring was continued for 30 minutes while maintaining the temperature at 0 ° C., and 0.02 parts of cumene hydroperoxide was added, followed by stirring for 30 minutes or more to complete the polymerization, and the poly (methyl methacrylate) polymer latex having a latex particle diameter of 120 nm was added. Obtained.

(II) Polymerization of rubbery polymer: Subsequently, the solid content of the polymethyl methacrylate-based polymer latex was equivalent to 42.86 parts (the total weight of the finally obtained graft polymer solid content). (Equivalent to 30% by weight) into a reactor equipped with a stirrer, and pure water 13 was added thereto as initial pure water.
9 parts (the solid content in the graft copolymer latex obtained by polymerizing the entire graft part to the final part was adjusted to be about 40% by weight. The following Examples 15 to 20 and Comparative Examples 6 to
In the same manner as in Example No. 10, the initial amount of pure water was set so that the solid content in the finally obtained graft polymer latex was about 40% by weight), followed by 0.292 parts of sodium oleate and naphthalene 0.114 parts of sodium sulfonate, ferrous sulfate _{(FeSO 4 · 7H 2 O)} 0.
00286 parts, 0.00571 part of ethylenediaminetetraacetic acid.2Na salt, 0.114 part of sodium formaldehyde sulfoxylate, and 0.286 part of sodium phosphate dodecahydrate were charged, and the inside of the reactor was purged with nitrogen to form a space. After removing oxygen from water and water, the content was heated to 50 ° C. while stirring. To this, a monomer mixture of 69.3 parts of butyl acrylate containing 0.042 parts of cumene hydroperoxide prepared in advance and 0.7 parts of allyl methacrylate, and 0.1 ml of sodium oleate were added.
An aqueous sodium oleate solution obtained by dissolving 5 parts in 15 parts of pure water was supplied to the reactor while continuously mixing and emulsifying using a pipeline homomixer over 3.5 hours. A part of the emulsion was sampled and evaluated (1) and (2). Table 4 shows the results. Stirring was continued for 1 hour or more while the content was kept at 50 ° C. to complete the polymerization, and a composite latex of poly (methyl methacrylate) / rubber-like polymer was obtained.

(III) Polymerization of graft portion: cumene hydroperoxide was added to the above composite latex in an amount of 0.03.
24 parts of methyl methacrylate and 6 parts of butyl acrylate
Parts of the monomer mixture were continuously added over 1.5 hours. Stirring was continued for 1 hour or more while the content was kept at 50 ° C. to complete the polymerization, and a graft copolymer latex having a latex particle diameter of 180 nm was obtained. Evaluations (3) to (6) were performed using a part of the graft copolymer latex. Table 5 shows the results.

(IV) 5 parts of calcium chloride was added to the obtained graft copolymer latex to carry out salting out and coagulation.
The mixture was heated to 0 ° C., dehydrated, washed and dried to obtain a white powdery graft copolymer having an average particle size of about 80 μm.

(V) Evaluations (7) and (8) were performed using the obtained powdery graft copolymer (12 parts of the graft copolymer was used for 90 parts of the vinyl chloride resin). . Table 5 shows the results.

Example 15 In (I), 0.6% of cumene hydroperoxide was added.
112 parts of methyl methacrylate, 80 parts of styrene,
And a monomer mixture comprising 8 parts of allyl methacrylate to prepare a methyl methacrylate-styrene polymer latex. In (II), 0.03 parts of sodium oleate was used for emulsification of the monomer mixture. Example 14 was the same as Example 14 except that an aqueous solution of sodium oleate prepared from 15 parts of pure water was used. The results are shown in Tables 4 and 5.

Examples 16 and 17 The procedure of Example 14 was repeated except that a monomer mixture for graft polymerization having the composition shown in Table 4 was used. The results are shown in Tables 4 and 5.

Example 18 Instead of continuously adding a monomer mixture containing cumene hydroxy peroxide to a reactor to prepare and use a poly (methyl methacrylate) polymer latex in (I), titanium dioxide particles 100 In the same manner as in Example 14, except that a dispersion of the titanium dioxide particles was used instead of the polymethyl methacrylate-based polymer latex in (II), And The results are shown in Tables 4 and 5.

Example 19 Example 18 was repeated except that precipitated calcium carbonate fine particles whose surface was coated with stearic acid were used instead of titanium dioxide.
The same as above. The results are shown in Tables 4 and 5.

Example 20 Example 20 was the same as Example 14 except that the following changes were made in (II) and (III). The results are shown in Tables 4 and 5.

In (II), the solid content of the polymethyl methacrylate-based polymer latex was changed to 150 parts (corresponding to 60% by weight of the total weight of the finally obtained graft polymer solids) of the initial pure water. Then, 155 parts of pure water was added, and then 0.025 part of sodium oleate was charged. After the inside of the reactor was replaced with nitrogen to remove oxygen in the space and water, the content was heated to 50 ° C. while stirring. did. Add cumene hydroperoxide to 0.03
Of a monomer mixture of 49.5 parts of butyl acrylate and 0.5 part of allyl methacrylate, and an aqueous solution of sodium oleate in which 0.5 part of sodium oleate was dissolved in 10 parts of pure water, for 2.5 hours And feed it to the reactor while mixing and emulsifying continuously using a pipeline homomixer,
In (III), cumene hydroperoxide 0.1.
A monomer mixture of 40 parts of methyl methacrylate, including 05 parts, and 10 parts of butyl acrylate was continuously added over 2.5 hours.

Comparative Examples 6 to 8 In (II), a monomer mixture of 69.3 parts of butyl acrylate containing 0.042 parts of cumene hydroperoxide and 0.7 part of allyl methacrylate alone was used for 3.5 hours. And the sodium oleate aqueous solution (the amount of sodium oleate / 15 parts of pure water shown in Table 4) was added twice every 70 minutes during the addition of the monomer mixture. The procedure was the same as in Example 14 except for the above. The results are shown in Tables 4 and 5.

Comparative Example 9 In (II), 150 parts of pure water was added to the poly (methyl methacrylate) polymer latex, 6.93 parts of butyl acrylate containing 0.0042 parts of cumene hydroperoxide and 0% of allyl methacrylate were added. 0.07 parts of a monomer mixture and an aqueous solution of sodium oleate (0.5 parts of sodium oleate / 4 parts of pure water) were continuously added over 21 minutes. Same as Example 14 except that a monomer mixture of 74.4 parts of methyl methacrylate containing 0.093 parts of peroxide and 18.6 parts of butyl acrylate was continuously added over 4 hours and 40 minutes. . The results are shown in Tables 4 and 5.

Comparative Example 10 In (II), 134 parts of pure water was added to the poly (methyl methacrylate) polymer latex, and 99 parts of butyl acrylate containing 0.06 part of cumene hydroperoxide and 1 part of allyl methacrylate were used. A monomer mixture and an aqueous sodium oleate solution (sodium oleate 0.5
Parts / pure water 20 parts), and the same procedure as in Example 14 was carried out except that continuous addition was carried out over 5 hours and polymerization of the graft part of (III) was not carried out. The results are shown in Tables 4 and 5.

[0087]

[Table 4]

[0088]

[Table 5]

Example 21 In Example 1 (I), the amount of sodium oleate initially used was changed to 0.06 parts, and in (II), a monomer mixture for graft portion polymerization having a composition shown in Table 6 was used. The use of liquid and evaluation in (IV) (7) and (8)
Was carried out in the same manner as in Example 1 except that 90 parts of the cycloolefin copolymer was used instead of 90 parts of the vinyl chloride resin. The results are shown in Tables 6 and 7.

In Comparative Examples 11 and 12 (II), only the monomer mixture was continuously supplied to the reactor over 4 hours, and a sodium oleate aqueous solution (the amount of sodium oleate / pure water shown in Table 6) was used. Fifteen
Part) was added in the same manner as in Example 21 except that the monomer mixture was added in three equal portions every hour during the addition of the monomer mixture. The results are shown in Tables 6 and 7.

[0091]

[Table 6]

[0092]

[Table 7]

[0093]

According to the method for producing a graft copolymer of the present invention, the amount of scale generated during the emulsion polymerization of a graft copolymer can be reduced with a small amount of a surfactant. it can. As a result, it is possible to produce a graft copolymer with stable quality, high production efficiency, a small amount of residual impurities, and a small amount of waste water when isolating the graft copolymer, and having little adverse effect on the environment. is there. Further, by using the graft copolymer produced according to the present invention, it becomes possible to obtain a resin molded product having excellent thermal stability and less coloring during molding. Further, since the quality of the graft copolymer is stable, it is possible to produce a high quality resin molded product with good reproducibility.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BC021 BC061 BD041 BD051 BD181 BG041 BG061 BG101 BK001 BN112 BN122 BN142 BN202 CE001 CF001 CG001 CH001

Claims (24)

[Claims] 1. A monomer mixture (i) having a composition to give a rubbery polymer comprising at least one monomer in the presence or absence of particles (i) dispersed in an aqueous medium.
i) 70 to 5 parts by weight of a monomer mixture (iii) having a composition to give a hard polymer composed of at least one monomer after polymerizing 30 to 95 parts by weight in one or more stages.
i) and (iii) of 100 parts by weight) in one or more stages to produce a multistage graft copolymer, in the polymerization of the monomer mixture (ii), at least the monomer mixture (ii) A method for producing a graft copolymer, wherein a part or all of the mixture is supplied to a polymerization tank as a mixed solution (iv) brought into contact with an aqueous medium and a surfactant. 2. The method for producing a graft copolymer according to claim 1, wherein the mixture (iv) is a dispersion. 3. The method for producing a graft copolymer according to claim 2, wherein a dispersion having a number average dispersed particle size of the dispersed phase of 300 μm or less is used. 4. An aqueous medium and a surfactant are continuously used until at least part or all of the monomer mixture (ii) is transferred from a storage facility for the monomer mixture (ii) to a polymerization tank. 3. The method for producing a graft copolymer according to claim 2, wherein the dispersion is supplied into a polymerization tank as a dispersion prepared by contacting the graft copolymer. 5. An aqueous medium and at least part or all of the monomer mixture (ii) in a storage facility for the monomer mixture (ii) or in a stirred tank for preparing a dispersion. The method for producing a graft copolymer according to claim 2, wherein the dispersion is supplied into a polymerization tank as a dispersion prepared by contacting with a surfactant. 6. In the case where the monomer mixture (ii) is polymerized in two or more stages, at least 20% by weight of the total amount of the monomer mixture (ii) is used as a dispersion. 3. The method for producing a graft copolymer according to item 2. 7. A monomer mixture (ii) contained in a dispersion.
3. The method according to claim 2, wherein the surfactant is used in an amount of 0.02 to 3 parts by weight and the aqueous medium is used in an amount of 8 to 200 parts by weight per 100 parts by weight. 8. The monomer mixture (ii) contains 2 to 1 carbon atoms.
The method for producing a graft copolymer according to claim 1, wherein at least 55% by weight of at least one alkyl acrylate monomer having two alkyl groups is used. 9. The method according to claim 1, wherein the monomer mixture (ii) contains 0.1 to 5% by weight of a polyfunctional monomer.
A method for producing the graft copolymer according to the above. 10. The monomer mixture (ii) has 2 to 2 carbon atoms.
2. The method according to claim 1, wherein at least 55% by weight of at least one alkyl acrylate monomer having 12 alkyl groups and 0.1 to 5% by weight of a polyfunctional monomer.
A method for producing the graft copolymer according to the above. 11. The process for producing a graft copolymer according to claim 1, wherein the particles (i) dispersed in an aqueous medium are not used. 12. Particles (i) dispersed in an aqueous medium
Is 45% by weight of the total amount of the graft copolymer in solid content.
The method for producing a graft copolymer according to claim 1, wherein: 13. Particles (i) dispersed in an aqueous medium
The method for producing a graft copolymer according to claim 12, wherein polymer particles are used. 14. A polymer particle comprising at least one alkyl acrylate monomer having an alkyl group having 2 to 12 carbon atoms and at least one alkyl methacrylate ester having an alkyl group having 1 to 12 carbon atoms. Monomer,
Aromatic vinyl monomer, conjugated diene, vinyl cyanide monomer, acrylamide monomer, methacrylamide monomer,
At least one selected from the group consisting of at least one alkyl amide monomer having an alkyl group having 1 to 16 carbon atoms and at least one alkyl amide monomer having at least one alkyl group having 1 to 16 carbon atoms. 14. The method for producing a graft copolymer according to claim 13, comprising a polymer of one kind of monomer or a monomer mixture containing the monomer. 15. Particles (i) dispersed in an aqueous medium
The method for producing a graft copolymer according to claim 12, wherein inorganic particles are used. 16. Particles (i) dispersed in an aqueous medium
The method for producing a graft copolymer according to claim 12, wherein organic-inorganic composite particles are used. 17. The monomer mixture (iii) contains 1 carbon atom
At least one alkyl methacrylate monomer having an alkyl group of from 12 to 12, at least one alkyl acrylate monomer having an alkyl group of from 2 to 12 carbon atoms, an aromatic vinyl monomer, Use of a monomer mixture containing at least one monomer selected from the group consisting of vinyl monomers, monoethylenically unsaturated carboxylic acids, vinyl monomers containing epoxy groups and polyfunctional monomers The method for producing a graft copolymer according to claim 1, wherein: 18. A graft copolymer produced by the method for producing a graft copolymer according to claim 1. 19. The graft copolymer according to claim 18, which has at least one shape selected from powder, granules, slurry, pellets, and strands. 20. A thermoplastic resin composition comprising the graft copolymer according to claim 18. 21. With respect to 100 parts by weight of the thermoplastic resin,
A thermoplastic resin composition comprising 1 to 70 parts by weight of the graft copolymer according to claim 18. 22. Thermoplastic resins include vinyl chloride resins, chlorinated vinyl chloride resins, acryl vinyl chloride resins, methyl methacrylate resins, acrylonitrile-styrene resins, methyl methacrylate-styrene resins, styrene resins, polycarbonate resins, polyester resins, and polyester resins. 21. The thermoplastic resin composition according to claim 20, wherein at least one resin or resin composition selected from the group consisting of an ether resin and a cycloolefin copolymer resin is used. 23. The method according to claim 2, wherein the thermoplastic resin contains at least 80% by weight of a vinyl chloride resin.
The thermoplastic resin composition according to 0. 24. A molded article comprising the thermoplastic resin composition according to claim 20.