JP2007326997A - Method for producing rubber-like polymer, rubber-like polymer, graft copolymer and thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a rubber-like polymer, which produces a rubber-like polymer for obtaining a graft copolymer for easily regulating processability while improving weather resistance and impact resistance. <P>SOLUTION: The method for producing a rubber-like polymer comprises subjecting a first raw material monomer to emulsion polymerization to produce acrylic rubber (A1), supplying a second raw material monomer in the presence of the acrylic rubber (A1) for 5 minutes-10 hours and starting an emulsion polymerization simultaneously with the supply to produce acrylic rubber (A2). One of the first raw material monomer and the second raw material monomer comprises a specific (meth)acrylate and the other comprises n-butyl acrylate. The glass transition temperature of the acrylic rubber obtained by the emulsion polymerization of the raw material monomer containing the specific (meth) acrylate is lower than that of the acrylic rubber obtained by the emulsion polymerization of the raw material monomer containing n-butyl acrylate. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rubbery polymer constituting a graft copolymer and a method for producing the same. The present invention also relates to a graft copolymer that is an impact modifier containing a rubbery polymer. Furthermore, it is related with the thermoplastic resin composition containing a graft copolymer and a thermoplastic resin.

For thermoplastic resins such as styrene resins, acrylic resins, polyvinyl chloride resins, polycarbonate resins, and polyester resins, a rubber copolymer is blended with a graft copolymer obtained by polymerizing vinyl monomers. Thus, it is widely known to improve impact resistance.
As the graft copolymer, for example, an MBS copolymer obtained by graft-polymerizing methyl methacrylate, styrene, acrylonitrile or the like to a butadiene rubber polymer may be used. However, since the butadiene-based rubbery polymer deteriorates when irradiated with ultraviolet rays, the impact resistance is reduced when the molded article of the thermoplastic resin composition containing the MBS copolymer is used outdoors, that is, the weather resistance is low. There was a problem.
As a countermeasure, Patent Document 1 discloses an acrylic rubber graft having a specific particle size distribution in which two types of polyalkyl (meth) acrylate rubbers having different glass transition temperatures are combined instead of a butadiene rubber polymer. It has been proposed to use a copolymer.

However, when the graft copolymer described in Patent Document 1 is blended with a thermoplastic resin, the melt viscosity of the resulting thermoplastic resin composition tends to increase. When the melt viscosity is increased, the resin temperature during the molding process increases due to the influence of the shear during mixing, and the thermoplastic resin may be thermally decomposed.
In addition, even when the molding temperature is increased to lower the melt viscosity, the thermoplastic resin is likely to be thermally decomposed. Therefore, when the graft copolymer was blended, the temperature range of the molding process was narrow and the processability was low.
Such a problem is observed in various thermoplastic resins, but the above problem appears remarkably because the polyvinyl chloride resin has the property of easily causing thermal decomposition by dehydrochlorination. In particular, in recent years, heat stabilizers added to polyvinyl chloride resins from the viewpoint of suppressing heavy metal emission are being replaced by calcium-zinc heat stabilizers from lead heat stabilizers that have been widely used so far. However, when the calcium-zinc heat stabilizer is used, the above problem becomes particularly remarkable. That is, since the calcium-zinc heat stabilizer has low external lubricity, it is necessary to add a lubricant separately. However, when a lubricant is added, it is necessary to increase the molding temperature in order to improve kneadability. It becomes the condition that the vinyl chloride resin is easily decomposed. On the other hand, if no lubricant is added, the melt viscosity becomes high, and the resin temperature rises due to the influence of the shear at the time of mixing, etc., so the thermal decomposition is also promoted.
JP 2005-89604 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a rubbery polymer for obtaining a graft copolymer capable of easily adjusting workability while improving weather resistance and impact resistance. And Moreover, it aims at providing the manufacturing method of the rubbery polymer which can manufacture such a rubbery polymer with high productivity. Another object of the present invention is to provide a graft copolymer that can easily adjust processability while improving weather resistance and impact resistance when blended in a thermoplastic resin. Furthermore, it aims at providing the thermoplastic resin composition which has high weather resistance and impact resistance, and can adjust workability easily.

In the invention for solving the above problems, an acrylic rubber (A1) is produced by emulsion polymerization of a first raw material monomer, and the second raw material monomer is added in the presence of the acrylic rubber (A1). A method for producing a rubbery polymer, which is supplied in a range of minutes to 10 hours and starts emulsion polymerization simultaneously with the supply to produce acrylic rubber (A2),
The first raw material monomer includes (meth) acrylate represented by the following chemical formula (I), the second raw material monomer includes n-butyl acrylate, or the first raw material monomer is n-butyl acrylate is included, and the second raw material monomer includes (meth) acrylate represented by the following chemical formula (I):
Acrylic rubber obtained by emulsion polymerization of a raw material monomer containing n-butyl acrylate having a glass transition temperature of acrylic rubber obtained by emulsion polymerization of a raw material monomer containing (meth) acrylate represented by the following chemical formula (I) A method for producing a rubbery polymer, characterized in that the temperature is lower than the glass transition temperature of rubber.
Further, a rubbery polymer produced by the production method, a graft copolymer obtained by graft polymerizing a raw material monomer for grafting to the rubbery polymer, and the graft copolymer and a thermoplastic resin. It is a thermoplastic resin composition to be contained.

(In the chemical formula (I), R ¹ is a hydrogen atom or a methyl group, and R ² is composed of a substituent having a branched chain, an alkylene group having a hydroxyl group or an alkoxyl group at the terminal, and an alkyl group having 12 or more carbon atoms. And at least one substituent selected from the group.)

  In the present invention, “(meth) acrylate” is a general term for acrylate and methacrylate.

According to the method for producing a rubbery polymer of the present invention, it is possible to produce a rubbery polymer for obtaining a graft copolymer capable of easily adjusting processability while improving weather resistance and impact resistance.
The rubbery polymer of the present invention can produce a graft copolymer that can easily adjust processability while improving weather resistance and impact resistance.
The graft copolymer of the present invention can easily adjust processability while improving weather resistance and impact resistance.
The thermoplastic resin composition of the present invention has high weather resistance and impact resistance, and can easily adjust processability.

One embodiment of the rubbery polymer of the present invention will be described.
The method for producing a rubbery polymer according to this embodiment includes a step of producing an acrylic rubber (A1) by emulsion polymerization of a first raw material monomer (hereinafter referred to as a first step), and a first step. The second raw material monomer is supplied in a range of 5 minutes to 10 hours to the reaction vessel charged with the latex of the acrylic rubber (A1) obtained by the above, and emulsion polymerization is started simultaneously with the supply of the acrylic rubber ( A2) is a method having a process (hereinafter referred to as a second process).

  The first raw material monomer in the first step contains (meth) acrylate represented by the above chemical formula (I) or contains n-butyl acrylate.

When the first raw material monomer contains the (meth) acrylate represented by the chemical formula (I), R ² in the chemical formula (I) is a substituent having a branched chain, and an alkylene having a hydroxyl group or an alkoxyl group at the terminal. And at least one substituent selected from the group consisting of a group and an alkyl group having 12 or more carbon atoms. Among these, since the effect of this invention is exhibited more, the substituent which has a branched chain, and / or a C12 or more alkyl group are preferable.

Specific examples of (meth) acrylate in which R ^{2 in} chemical formula (I) is a substituent having a branched chain include 2-ethylhexyl acrylate and methoxytripropylene glycol acrylate. Specific examples of the (meth) acrylate in which R ^{2 in the} chemical formula (I) is an alkylene group having a hydroxyl group or an alkoxyl group at the terminal include ethoxyethyl acrylate and 4-hydroxybutyl acrylate. Here, methoxytripropylene glycol acrylate is also an example of (meth) acrylate in which R ^{2 in} chemical formula (I) is an alkylene group having an alkoxyl group at the terminal. Specific examples of (meth) acrylate in which R ^{2 in the} chemical formula (I) is an alkyl group having 12 or more carbon atoms include tridecyl methacrylate and stearyl methacrylate.
Among these (meth) acrylates, 2-ethylhexyl acrylate is preferably used because the impact resistance of the thermoplastic resin composition using the rubbery polymer is further improved. Moreover, these (meth) acrylates may be used individually by 1 type, and may use 2 or more types together.

  The content of the (meth) acrylate in the first raw material monomer is 70% by mass or more because the impact resistance of the thermoplastic resin composition using the rubber polymer is further improved. Is more preferable, and 90% by mass or more is more preferable.

  When the first raw material monomer includes n-butyl acrylate, the n-butyl acrylate content in the first raw material monomer is determined by the impact resistance of the thermoplastic resin composition using the rubber polymer. In view of further improving the properties, the content is preferably 70% by mass or more, and more preferably 90% by mass or more.

The first raw material monomer may include a monomer having two or more unsaturated bonds in the molecule (hereinafter referred to as a polyfunctional monomer). The polyfunctional monomer functions as a crosslinking agent or a graft crossing agent.
Examples of the polyfunctional monomer that functions as a crosslinking agent include ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, divinylbenzene, and polyfunctional methacrylic groups. Examples include modified silicone.
Examples of the polyfunctional monomer that functions as a graft crossing agent include allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, and the like. However, allyl methacrylate can also be used as a crosslinking agent.
A polyfunctional monomer may be used individually by 1 type, and may use 2 or more types together.
The content of the polyfunctional monomer contained in the first raw material monomer is 2% by mass or less because the balance of the physical properties of the thermoplastic resin composition using the rubbery polymer becomes good. Preferably, 1.5 mass% or less is more preferable.

The first raw material monomer includes a monomer other than the (meth) acrylate or n-butyl acrylate represented by the chemical formula (I) and the polyfunctional monomer (hereinafter referred to as other monomer). ) May be included. Examples of other monomers include various types such as aromatic alkenyl compounds such as styrene, α-methylstyrene, and vinyl toluene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, methacrylic acid-modified silicone, and fluorine-containing vinyl compounds. And vinyl monomers.
The content of the other monomer contained in the first raw material monomer is 30% by mass or less from the viewpoint of impact resistance of the thermoplastic resin composition using the rubbery polymer. preferable.

The first raw material monomer is preferably preliminarily emulsified. If the first raw material monomer is preliminarily emulsified, scale adhesion during emulsion polymerization can be prevented and the polymerization rate can be increased.
As a method of the emulsification treatment, for example, first, a first emulsifier such as a homogenizer capable of applying a pressure of 5 MPa or more after preliminarily dispersing the first raw material monomer using a mixing device such as an in-line mixer is used. And a method of performing this emulsification. The average particle diameter of the emulsion of the first raw material monomer thus obtained is about 0.1 to 10 μm.
Moreover, as a method of an emulsification process, the method of stirring the 1st raw material monomer in presence of an emulsifier is mentioned.

As an emulsifier for emulsifying the first raw material monomer in the first step, an anionic surfactant, a nonionic surfactant, a cationic surfactant or the like can be used, and two or more kinds are used as necessary. These surfactants may be used in combination.
Specific examples of emulsifiers include sulfate-based emulsifiers such as sodium lauryl sulfate, sulfonic acid-based emulsifiers such as sodium alkylbenzene sulfonate and sodium alkyldiphenyl ether sulfonate, other sulfosuccinic acid-based emulsifiers, amino group-containing emulsifiers, mono-fatty acids and succinic acid. Examples include fatty acid-based emulsifiers containing acid.
Examples of the polymerization initiator used in the polymerization include organic peroxides such as t-butyl hydroperoxide and benzoyl peroxide, inorganic peroxides such as sodium persulfate and potassium persulfate, and azoisobutyronitrile. An azo compound such as can be used. Further, a reducing agent made of a mixture of ferrous sulfate, ethylenediaminetetraacetic acid disodium salt and Rongalite may be added to the organic peroxide, inorganic peroxide, and azo compound.
The polymerization of the first raw material monomer may be performed in one stage or in multiple stages.
The latex of acrylic rubber (A1) is obtained by emulsion polymerization in the first step.

The second raw material monomer supplied to the latex of acrylic rubber (A1) obtained in the first step contains n-butyl acrylate, or (meth) acrylate represented by the above chemical formula (I) Is included.
However, when the first raw material monomer contains (meth) acrylate represented by the chemical formula (I), the second raw material monomer contains n-butyl acrylate, When the first raw material monomer contains n-butyl acrylate, the second raw material monomer contains (meth) acrylate represented by the above chemical formula (I).

  The second raw material monomer may contain the same polyfunctional monomer as the first raw material monomer, or may contain other monomers. When both the first raw material monomer and the second raw material monomer contain a polyfunctional monomer, from the viewpoint of impact resistance of the thermoplastic resin composition using the rubber polymer. It is preferable that the mass ratio contained in the polyfunctional monomer in the second raw material monomer is larger than the mass ratio of the polyfunctional monomer contained in the first raw material monomer.

In the second step, the second raw material monomer is supplied to the reaction vessel charged with the acrylic rubber (A1) latex in the range of 5 minutes to 10 hours, and emulsion polymerization is started simultaneously with the supply. Acrylic rubber (A2) is produced. The supply time of the second raw material monomer is preferably in the range of 10 minutes to 9 hours, more preferably in the range of 15 minutes to 8 hours. If the supply time of the second raw material monomer is less than 5 minutes, the processability of the thermoplastic resin composition when the rubbery polymer is used is lowered, and the occurrence of cullet tends to increase during the polymerization. is there. When the supply time exceeds 10 hours, the productivity of the rubbery polymer decreases.
The emulsion polymerization of the second raw material monomer is started at the same time as the second raw material monomer is supplied to the reaction vessel charged with the acrylic rubber (A1) latex. The emulsion polymerization of the second raw material monomer does not need to be completed during the supply time of 5 minutes to 10 hours, and may be completed during the subsequent holding time.
As a method for supplying the second raw material monomer, dropping is preferred.
As a method for initiating the emulsion polymerization, for example, where a reducing agent is present, a mixture of the second raw material monomer and peroxide is added to activate the polymerization initiator, and the activated polymerization start And a method of initiating polymerization with an agent.

As an emulsifier and a polymerization initiator for polymerizing the second raw material monomer, the same ones used in the first step can be used. In the second step, the emulsifier contained in the latex of the acrylic rubber (A1) may be used as it is without newly adding an emulsifier.
The polymerization of the second raw material monomer may be performed in one stage or may be performed in multiple stages.

In the second step, since the impact resistance of the thermoplastic resin composition using the rubbery polymer is sufficiently exhibited, the ratio of the acrylic rubber (A1) to the acrylic rubber (A2) is set to acrylic rubber (A1). It is preferable to select the charged amount of the acrylic rubber (A1) and the added amount of the second raw material monomer so as to be 5 to 95% by mass and the acrylic rubber (A2) 95 to 5% by mass.
More preferably, the acrylic rubber (A1) is 10 to 90% by mass and the acrylic rubber (A2) is 90 to 10% by mass. Furthermore, the acrylic rubber (A1) is 10 to 85% by mass, and the acrylic rubber (A2). It is particularly preferable that the content be 90 to 15% by mass.

The glass transition temperature (Tg ₁ ) of the acrylic rubber (A1) and the glass transition temperature (Tg ₂ ) of the acrylic rubber (A2) are the resistance of the thermoplastic resin composition using the graft copolymer containing the rubbery polymer. Both of them are preferably 10 ° C. or less because of high impact properties.

Further, in this method for producing a rubbery polymer, the glass transition temperature of acrylic rubber obtained by emulsion polymerization of a raw material monomer containing (meth) acrylate represented by the chemical formula (I) is n-butyl acrylate. It is made to become lower than the glass transition temperature of the acrylic rubber obtained by emulsion polymerization of the raw material monomer containing.
The glass transition temperature of the acrylic rubber obtained by emulsion polymerization of the raw material monomer containing (meth) acrylate represented by the chemical formula (I) is obtained by emulsion polymerization of the raw material monomer containing n-butyl acrylate. In order to make the temperature lower than the glass transition temperature of acrylic rubber, for example, the main component of the raw material monomer containing (meth) acrylate represented by the chemical formula (I) may be 2-ethylhexyl acrylate. .

  Here, the glass transition temperature corresponds to a peak when a storage elastic modulus and a loss elastic modulus are measured by a dynamic viscoelasticity measuring apparatus (hereinafter referred to as DMS), and tan δ which is a loss elastic modulus / storage elastic modulus is plotted. Temperature. Generally, a polymer has a specific glass transition temperature. When a plurality of components are combined, the glass transition temperature of each component is observed. When the polymer is composed of two components as in the present invention, two glass transition temperatures are observed. In addition, when the ratio of each component is biased or when the glass transition temperatures are close to each other, the peaks may approach each other, but can be easily discriminated by DMS.

  As a result of intensive studies by the present inventors, the thermoplastic resin composition using the rubbery polymer obtained by the above-described method for producing a rubbery polymer can be easily processed while improving the weather resistance and impact resistance. It was found that it can be adjusted.

The rubbery polymer of the present invention is produced by the above-described method for producing a rubbery polymer.
The average particle size of the rubber polymer is preferably 80 to 1500 nm, and more preferably 100 to 700 nm from the viewpoint of general impact resistance. However, in the case of improving the impact resistance of the polycarbonate resin or the polyvinyl chloride resin, it is particularly preferably 100 to 300 nm, and in the case of improving the impact resistance of a brittle polymer such as polystyrene, 300 to 300 nm. Particularly preferred is 1200 nm.
The average particle diameter of the rubbery polymer is a value measured by capillary hydrodynamic flow fractionation (hereinafter also referred to as CHDF).
In order to adjust the average particle diameter of the rubbery polymer to the above range, for example, the conditions such as the amount of the emulsifier used in the first step and the second step, the amount of the polymerization initiator, and the polymerization time are appropriately changed. do it. For example, the larger the amount of emulsifier, the smaller the average particle size.

  The graft copolymer of the present invention is obtained by graft polymerization of the above-mentioned rubbery polymer with a raw material monomer for grafting. In the present specification, a polymer of a raw material monomer for grafting polymerized on a rubbery polymer is referred to as a graft portion.

  Specific examples of the raw material monomer for grafting include aromatic alkenyl compounds such as styrene, α-methylstyrene, vinyltoluene; methyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, glycidyl methacrylate, etc. (Meth) acrylates; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. These raw material monomers for grafting may be used alone or in combination of two or more.

The raw material monomer for grafting may include the polyfunctional monomer used in the production of the rubbery polymer. When the grafting raw material monomer contains a polyfunctional monomer, when the graft polymer is used, the impact resistance of the thermoplastic resin composition becomes higher and the heat resistance is also improved. .
However, the content of the polyfunctional monomer in the raw material monomer for grafting is preferably 20% by mass or less from the viewpoint of the balance of physical properties of the thermoplastic resin composition.

  The ratio of the rubbery polymer and the graft part in the graft copolymer is preferably 70 to 99% by mass, preferably 80 to 95% by mass when the total of both is 100% by mass. It is more preferable that it is 80-90 mass%. If the ratio of the rubbery polymer is 70% by mass or more, the effect of improving the impact resistance of the graft copolymer becomes higher. If the ratio of the rubbery polymer is 99% by mass or less, the graft copolymer The dispersibility of the coalescence in the thermoplastic resin becomes high, and the processability of the thermoplastic resin composition becomes higher.

The graft copolymer may contain an inorganic filler. If the inorganic filler is contained, thermal deformation of the thermoplastic resin composition can be prevented when the graft copolymer is used.
Examples of the inorganic filler include carbonates such as heavy calcium carbonate, precipitated calcium carbonate, and colloidal calcium carbonate, titanium oxide, clay, talc, mica, silica, carbon black, graphite, glass beads, glass fiber, carbon fiber, A metal fiber etc. are mentioned.
When an inorganic filler is included in the graft copolymer, a water-soluble or suspended filler may be added directly to the graft copolymer latex, or at the time of powder recovery or further pelletizing. You may add to.
The content of the inorganic filler in the graft copolymer is preferably 0.01 to 30 parts by mass, more preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the graft copolymer. The amount is particularly preferably 0.01 to 10 parts by mass, and most preferably 0.01 to 5 parts by mass. If content of an inorganic filler is 0.01 mass part or more, the heat resistance of a thermoplastic resin composition will become high, and if it is 30 mass parts or less, a fall of impact resistance can be prevented.

  Further, the graft copolymer may contain a calcium component. When the graft copolymer contains a calcium component, it is particularly effective for improving the impact resistance, weather resistance, and wet heat resistance of engineering plastics. The content of the calcium component is preferably in the range of 0.0001 to 10 parts by mass with respect to 100 parts by mass of the graft copolymer. The calcium source is not particularly limited.

Graft polymerization for obtaining the graft copolymer may be one-stage or multi-stage, but in order to improve impact resistance, multi-stage is preferable.
If the raw material monomer for grafting contains a reactive monomer such as glycidyl methacrylate, the dispersibility and the like can be improved while leaving the epoxy group of glycidyl methacrylate. preferable.
However, increasing the number of stages increases the number of manufacturing steps and decreases the productivity, so it is not preferable to increase more than necessary. Therefore, it is preferably 5 stages or less, and more preferably 3 stages or less.

  As the emulsifier and the polymerization initiator used in the graft polymerization, those similar to those used in the production of the rubbery polymer are used.

A latex containing a graft copolymer comprising a rubbery polymer and a graft portion is obtained by graft polymerization.
Examples of the method for recovering the graft copolymer from the latex containing the graft copolymer include spray drying, wet coagulation with an acid or salt, and the like. However, when the graft copolymer has a highly reactive functional group, wet coagulation with an acid is not preferable. This is because when an acid is used, the functional group may be deactivated.

When performing wet coagulation using a salt, it is preferable to use an alkaline earth metal salt such as calcium acetate, calcium chloride, or magnesium sulfate as the salt. If an alkaline earth metal salt is used, the heat and humidity resistance, that is, deterioration such as decomposition of the thermoplastic resin due to moisture and heat can be suppressed.
Examples of the acid used for wet coagulation include hydrochloric acid, sulfuric acid, and acetic acid.

Spray drying is a method of drying by spraying latex in a vacuum container, and has an advantage that addition of acid or salt can be omitted.
At the time of spray drying, simultaneously with the latex of the graft copolymer, a liquid containing the above-mentioned inorganic fillers, calcium component, and a polymer other than the graft copolymer (hard vinyl copolymer) may be co-sprayed. Good. When co-sprayed, the graft copolymer latex and inorganic fillers, calcium component, and a polymer other than the graft copolymer can be collected and mixed to adjust the powder properties of the graft copolymer. .

The shape of the graft copolymer may be any of powder, granules, and pellets.
In particular, when the thermoplastic resin to be blended when producing the thermoplastic resin composition is a pellet, the graft copolymer is preferably made into a granule or a pellet.
The pellets can be obtained by melting the graft copolymer to produce strands by an apparatus equipped with an extruder and a pelletizer, and cutting them at predetermined intervals. It can also be obtained by press molding.

The thermoplastic resin composition of the present invention contains the above-described graft copolymer and a thermoplastic resin.
Specific examples of the thermoplastic resin include olefin resins such as polypropylene (PP) and polyethylene (PE); polystyrene (PS), high impact polystyrene (HIPS), (meth) acrylate / styrene copolymer (MS), styrene.・ Acrylonitrile copolymer (SAN), styrene / maleic anhydride copolymer (SMA), acrylonitrile / butadiene / styrene copolymer (ABS), acrylonitrile / styrene / acrylate copolymer (ASA), acrylonitrile / EPDM / styrene Styrenic resin (St resin) such as copolymer (AES); Acrylic resin (Ac resin) such as polymethyl methacrylate (PMMA); Polycarbonate resin (PC resin); Polyamide resin (PA resin) Resin); polyethylene terephthalate PET), polyester resins such as polybutylene terephthalate (PBT) (PEs resins); (modified) polyphenylene ether resins (PPE resins), polyoxymethylene resins (POM resins), polysulfone resins (PSO) Engineering plastics), polyarylate resins (PAr resins), polyphenylene resins (PPS resins), thermoplastic polyurethane resins (PU resins), etc .; styrene elastomers, olefin elastomers, vinyl chloride elastomers , Urethane elastomers, polyester elastomers, polyamide elastomers, fluoroelastomers, thermoplastic elastomers (TPE) such as 1,2-polybutadiene and trans 1,4-polyisoprene; PC resins such as PC / ABS / St Resin alloy, PVC resin such as PVC / ABS / St resin alloy, PA resin such as PA / ABS / St resin alloy, PA resin / TPE alloy, PA resin such as PA / PP / polyolefin Resin alloy, PBT resin / TPE, PC resin such as PC / PBT / PEs resin alloy, polyolefin resin / TPE, alloy between olefin resins such as PP / PE, PPE / HIPS, PPE / PBT, PPE PPE resin alloys such as / PA, polyacetal resins (POM), PVC resins such as PVC / PMMA / polymer alloys such as Ac resin alloys; hard, semi-rigid, and soft vinyl chloride resins.
Among the thermoplastic resins, when the styrene resin, acrylic resin, polycarbonate resin, polyamide resin, polyester resin, polyacetal resin, and vinyl chloride resin are used, the effect of the present invention is more exhibited. Furthermore, the effects of the present invention are particularly exhibited when styrene resins, polycarbonate resins, polyester resins, and vinyl chloride resins are used, and the effects of the present invention are most exhibited when vinyl chloride resins are used. .

  The content of the graft copolymer in the thermoplastic resin composition is preferably 1 to 40 parts by mass and more preferably 1 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic resin. If the content of the graft copolymer is 1 part by mass or more, the impact resistance can be improved reliably, and if it is 40 parts by mass or less, the workability can be adjusted more easily.

The thermoplastic resin composition may include a stabilizer. Stabilizers can be divided into metallic stabilizers and non-metallic stabilizers.
Specific examples of metal stabilizers include lead stabilizers such as tribasic lead sulfate, dibasic lead phosphite, basic lead sulfite and lead silicate; potassium, magnesium, barium, zinc, cadmium, lead Metal soaps derived from 2-ethylhexanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, hydroxystearic acid, oleic acid, ricinoleic acid, linoleic acid, behenic acid, etc. System stabilizers; organotin stabilizers derived from alkyl groups, ester groups, etc. and fatty acid salts, maleates, sulfides, etc .; Ba—Zn series, Ca—Zn series, Ba—Ca—Sn series, Composite metal soap stabilizers such as Ca—Mg—Sn, Ca—Zn—Sn, Pb—Sn, and Pb—Ba—Ca; metals such as barium and zinc, and 2-ethylhexane , Branched fatty acids such as isodecanoic acid and trialkylacetic acid, unsaturated fatty acids such as oleic acid, ricinoleic acid and linoleic acid, alicyclic acids such as naphthenic acid, aromatics such as carboxylic acid, benzoic acid, salicylic acid and substituted derivatives thereof Examples thereof include metal salt stabilizers derived from usually two or more organic acids such as acids.
The form of the stabilizer may be a liquid form dissolved in an organic solvent such as petroleum hydrocarbon, alcohol, or glycerin derivative.

  Specific examples of non-metallic stabilizers include epoxy compounds such as epoxy resins, epoxidized soybean oil, epoxidized vegetable oil, and epoxidized fatty acid alkyl esters; dihydric alcohols such as propylene glycol to phosphoric acid, hydroquinone, and bisphenol A. An organic phosphite ester to which an aromatic compound is bonded and having a substituent such as an alkyl group, an aryl group, a cycloalkyl group or an alkoxyl group in the molecule; 2,4-di-t-butyl-3-hydroxytoluene (BHT) ), Hindered phenols such as bisphenol dimerized with sulfur or methylene groups, UV absorbers such as salicylic acid ester, benzophenone, benzotriazole; light stabilizers of hindered amines or nickel complex salts; carbon black, rutile type titanium oxide, etc. UV-screening agents: Trimerolpropane, pe Polyhydric alcohols such as enterythritol, sorbitol, mannitol; nitrogen-containing compounds such as β-aminocrotonate, 2-phenylindole, diphenylthiourea, dicyandiamide; sulfur-containing compounds such as dialkylthiodipropionate; acetoacetate And keto compounds such as dehydroacetic acid and β-diketone; organosilicon compounds; borate esters; These can be used alone or in combination of two or more.

  The thermoplastic resin composition may contain a filler. Specific examples of fillers include carbonates such as heavy calcium carbonate, precipitated calcium carbonate, and colloidal calcium carbonate; titanium oxide, clay, talc, mica, silica, carbon black, graphite, glass beads, glass fibers, carbon fibers And inorganic fillers such as metal fibers; organic fibers such as polyamide; organic fillers such as silicone; natural organic substances such as wood flour; and the like.

  Further, the thermoplastic resin composition may contain an impact modifier other than the graft copolymer, a plasticizer, a lubricant, a flame retardant, and a heat resistance improver, if necessary.

  Specific examples of impact modifiers include MBS copolymer, NBR (acrylonitrile / butadiene copolymer rubber), EVA (ethylene / vinyl acetate copolymer), chlorinated polyethylene, acrylic rubber, polyalkyl (meth) acrylate. Examples thereof include rubber-based graft copolymers and thermoplastic elastomers.

  Specific examples of the plasticizer include dibutyl adipate, alkyl esters of aromatic polybasic acids such as dibutyl phthalate, dioctyl phthalate, diisodecyl phthalate, diisononyl phthalate, diundecyl phthalate, trioctyl trimellitate, triisooctyl trimellitate; Alkyl esters of fatty acid polybasic acids such as dioctyl adipate, dithiononyl adipate, dibutyl azelate, dioctyl azelate, diisononyl azelate; phosphate esters such as tricresyl phosphate, adipic acid, azelaic acid, sebacic acid, phthalic acid And a polyhydric alcohol such as ethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, and 1,4-butylene glycol. Polyester plasticizers such as compounds in which the end of a polycondensate having a molecular weight of about 600 to 8,000 is sealed with a monohydric alcohol or monovalent carboxylic acid; epoxidized soybean oil, epoxidized linseed oil, epoxidized tall oil, Epoxy plasticizers such as fatty acid-2-ethylhexyl; chlorinated paraffin and the like.

  Specific examples of the lubricant include liquid hydrocarbons, pure hydrocarbons such as low molecular weight polyethylene, halogenated hydrocarbons, fatty acids such as higher fatty acids and oxy fatty acids, polyhydric alcohol esters of fatty acids such as fatty acid amides and glycerides, fatty alcohols of fatty acids Esters (ester waxes), metal soaps, fatty alcohols, polyhydric alcohols, polyglycols, polyglycerols, partial esters of fatty acids and polyhydric alcohols, fatty acids and polyglycols, esters of partial esters of polyglycerol, (meth) acrylates A copolymer etc. are mentioned.

  Specific examples of flame retardants include phosphate ester compounds, phosphite ester compounds, condensed phosphate ester compounds, aluminum hydroxide, antimony trioxide, antimony pentoxide and other acid antimony compounds, halogen-containing phosphate ester compounds, Halogen-containing condensed phosphate compounds, halogen-containing compounds such as brominated aromatic compounds such as chlorinated paraffins, brominated aromatic triazines, and brominated phenyl alkyl ethers, sulfone or sulfate compounds, and epoxy reaction flame retardants Etc.

  Specific examples of the heat resistance improver include (meth) acrylate copolymers, imide copolymers, styrene / acrylonitrile copolymers, and the like.

  Further, the thermoplastic resin composition includes a processing aid such as a (meth) acrylate copolymer, a release agent, a crystal nucleating agent, a fluidity improver, a colorant, an antistatic agent, a conductivity imparting agent, Surfactants, antifogging agents, foaming agents, antibacterial agents, and the like.

The method for producing the thermoplastic resin composition is not particularly limited, but the melt mixing method is preferable. Examples of the melt mixing apparatus used in the melt mixing method include an extruder, a Banbury mixer, a roller, and a kneader. The melt mixing apparatus is normally operated continuously, but may be batch-wise.
The mixing order of each component which comprises a thermoplastic resin composition is not specifically limited. In the melt mixing method, a small amount of solvent may be used as necessary.

In the above-mentioned thermoplastic resin composition, the rubbery polymer constituting the graft copolymer is acrylic rubber, and therefore has almost no unsaturated double bond and is excellent in weather resistance.
Further, as a result of intensive studies by the present inventors, a thermoplastic resin composition containing a graft copolymer using a rubbery polymer thus obtained and a thermoplastic resin has improved impact resistance. However, it has been found that the workability can be easily adjusted. By having such characteristics, for example, when a vinyl chloride resin is used as the thermoplastic resin, the gelation time as an index of the plasticizing time can be set as an index of the plasticizing time while improving the impact resistance. It can be changed according to the specifications.
Therefore, the thermoplastic resin composition of the present invention has high weather resistance and impact resistance, and the processability can be easily adjusted.

When the thermoplastic resin is a vinyl chloride resin and a Ca—Zn stabilizer is used as the thermal stabilizer, the gelation time is preferably 200 seconds or more and less than 400 seconds, and 200 seconds or more and less than 350 seconds. More preferably.
When the gelation time is less than 200 seconds, the melt viscosity increases rapidly, and the resin temperature at the time of molding rises due to the influence of the share when the thermoplastic resin composition is produced by the melt mixing method, May cause thermal decomposition of vinyl chloride resin. When the gelation time is 400 seconds or more, the productivity during processing of the thermoplastic resin composition tends to decrease.
The gelation time here is the time from the start of kneading until the kneading torque reaches a peak when the thermoplastic resin composition is kneaded with a Brabender plastic coder. This gel time is an indicator of plasticization time.

  Such thermoplastic resin compositions include, for example, hard building materials (window frames, sizing materials, pipes, joints), interior and exterior parts of automobiles, miscellaneous goods such as toys and stationery, OA equipment, home appliances, and other molding materials. Is preferably used.

Hereinafter, the present invention will be described in more detail with reference to examples.
In the following examples, the average particle diameter and glass transition temperature of the rubbery polymer were measured by the following methods.

<Measurement of average particle size of rubbery polymer>
The obtained rubber polymer latex was diluted with deionized water, and an average particle size was measured using a CHDF 2000 type particle size distribution meter manufactured by US MATEC, which is a particle size distribution meter by the CHDF method, using this as a sample. . The measurement conditions were standard conditions recommended by MATEC.
Specifically, using a special capillary cartridge for particle separation and carrier liquid, the liquidity is almost neutral, the flow rate is 1.4 ml / min, the pressure is about 4000 psi, and the temperature is kept at 35 ° C., and the concentration is about 3%. Of 0.1 ml of diluted latex sample. In addition, a calibration curve was prepared using a total of 8 monodisperse polystyrenes having a known particle size in the range of 0.02 μm to 0.8 μm manufactured by DUKE Corporation as a standard particle size substance.

<Measurement of glass transition temperature of rubbery polymer>
The graft copolymer containing a rubbery polymer was molded into a 3 mm thick plate using a press machine having a temperature set at 150 ° C. A test piece having a width of about 10 mm and a length of about 50 mm was cut out from the plate, and the temperature rise rate was 2 ° C./min using a DMS (dynamic viscoelasticity measuring device) manufactured by Seiko Electronics. Then, the storage elastic modulus and the loss elastic modulus were measured, and the loss elastic modulus / storage elastic modulus tan δ was plotted. The temperature corresponding to the peak of the tan δ plot was read. The temperature indicates the glass transition temperature.

Example 1
41 parts by mass of 2-ethylhexyl acrylate, allyl methacrylate in an amount corresponding to 0.5% by mass based on 100% by mass of 2-ethylhexyl acrylate, 0.01 parts by mass of disodium alkyldiphenyl ether sulfonate, 64 parts by mass of water Was pre-dispersed with a TK homomixer made by Special Machine Co., Ltd. at 12000 rpm for 5 minutes, and then forcibly emulsified with a homogenizer LB-40 manufactured by Goulin at a pressure of 20 MPa to obtain a pre-emulsion.
Next, the pre-emulsion was charged into a first separable flask equipped with a condenser and a stirring blade, and t in an amount corresponding to 0.5% by mass when 2-ethylhexyl acrylate in the pre-emulsion was 100% by mass. -Butyl hydroperoxide was charged into the separable flask.
Next, nitrogen was purged at room temperature at a rate of 200 ml / min for 35 minutes in the first separable flask, and then the temperature in the first separable flask was raised to 50 ° C. After reaching 50 ° C., a mixture of 0.0004 parts by mass of ferrous sulfate, 0.0012 parts by mass of disodium ethylenediaminetetraacetate, 0.10 parts by mass of Rongalite, and 5 parts by mass of distilled water was used as the first separable liquid. The solution was put into the flask, polymerization was started, and then held for 90 minutes to obtain a latex of acrylic rubber (A1).
Next, in a second separable flask equipped with a condenser and a stirring blade, which is different from the separable flask, 20 parts by mass of acrylic rubber (A1) latex in terms of solid content, disodium alkyldiphenyl ether sulfonate. A mixed solution of 7 parts by mass, ferrous sulfate 0.001 part by mass, ethylenediaminetetraacetic acid disodium salt 0.003 parts by mass, Rongalite 0.24 parts by mass and distilled water 10 parts was added. Subsequently, nitrogen was purged at room temperature at a rate of 200 ml / min for 35 minutes into the second separable flask, and then the temperature in the second separable flask was raised to 45 ° C.
68 parts by mass of n-butyl acrylate, allyl methacrylate in an amount corresponding to 2% by mass when n-butyl acrylate is 100% by mass, and 0.4% by mass when n-butyl acrylate is 100% by mass A second raw material monomer was prepared by mixing an amount corresponding to t-butyl peroxide.
The second raw material monomer was dropped into the second separable flask over 5 minutes, and polymerization was started simultaneously with the dropping. Thereafter, the inside of the second separable flask was held at 65 ° C. for 60 minutes to complete the polymerization of the acrylic rubber (A2) to obtain a latex of a rubbery polymer (G-1). The polymerization rate of this rubber-like polymer (G-1) was 99.9 mass%. Table 1 shows the average particle diameter of the rubber polymer (G-1).

Subsequently, 11 parts of methyl methacrylate and t-butyl peroxide in an amount corresponding to 0.5% by mass when 100% by mass of methyl methacrylate were mixed were mixed to prepare a raw material monomer for grafting.
The total amount (100 parts by mass) of the latex of the rubber-like polymer (G-1) was heated to a temperature of 65 ° C., and the grafting raw material monomer was dropped therein over 25 minutes. Then, the temperature was maintained for 60 minutes to complete the polymerization, and an acrylic rubber-based graft copolymer latex comprising a rubbery polymer and a graft portion was obtained.
Subsequently, the latex of the graft copolymer was dropped into 200 parts by mass of hot water containing 5.0% by mass of calcium acetate to coagulate, separate and wash the graft copolymer. The obtained wet graft copolymer was dried at 75 ° C. for 12 hours to obtain a powdered graft copolymer 1.
The obtained graft copolymer 1, vinyl chloride resin and additives were blended in the proportions shown in Table 2 to obtain a thermoplastic resin composition.

The following physical property evaluation was performed about the obtained thermoplastic resin composition. The evaluation results are shown in Table 3.
<Mechanical strength> Izod impact strength ASTM D256
The thermoplastic resin composition was kneaded at 190 ° C. for 4 minutes and then press-molded into a 100 cm square and 3 mm thick shape to obtain a roll sheet. A test piece according to ASTM D256 was cut out from this roll sheet, and the Izod impact strength was measured at 23 ° C. using the test piece.
<Pyrolysis and productivity> Measurement of gelation time using a Brabender plastic coder A Brabender PL2000 model manufactured by Brabender is equipped with a mixer-type head: W-50E3 zone as a plast mill, a container temperature of 140 ° C., a filling amount of 50 g, a holding time. The gelation time of the thermoplastic resin composition was measured under conditions of 4 minutes and a mixer rotation speed of 30 rpm. The gel time was measured for 11 minutes (660 seconds) after holding for 4 minutes.
The measured gelation time is short (specifically, less than 200 seconds), because the melt viscosity rises rapidly in a short time, so it is affected by the shear during melt mixing, etc. It shows that the resin temperature rises and the vinyl chloride resin is easily pyrolyzed (evaluation of thermal decomposability: x), and that the gelation time is long (specifically 400 seconds or more) means that the thermoplastic resin composition It shows that productivity at the time of processing becomes low (evaluation of productivity at processing: x).

(Example 2)
A rubber polymer (G-2) was obtained in the same manner as in Example 1 except that the second raw material monomer was dropped into the second separable flask over 3 hours.
A graft copolymer 2 was obtained in the same manner as in Example 1 except that the rubber polymer (G-2) was used. Further, a thermoplastic resin composition was obtained in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

(Comparative Example 1)
An acrylic rubber (A1) was obtained in the same manner as in Example 1. Separately from the separable flask used when synthesizing the acrylic rubber (A1), the latex of the acrylic rubber (A1) is 20 parts by mass in terms of solid content in a second separable flask equipped with a condenser and a stirring blade. In addition, 0.7 parts by mass of disodium alkyldiphenyl ether sulfonate was charged.
68 parts by mass of n-butyl acrylate, allyl methacrylate in an amount corresponding to 2% by mass when n-butyl acrylate is 100% by mass, and 0.4% by mass when n-butyl acrylate is 100% by mass A second raw material monomer was prepared by mixing an amount corresponding to t-butyl peroxide.
Next, after the second raw material monomer was charged all at once into the second separable flask and held for 35 minutes, 0.001 part by mass of ferrous sulfate, 0.003 part by mass of disodium ethylenediaminetetraacetate Then, a mixed solution of 0.24 parts by mass of Rongalite and 10 parts of distilled water was added to initiate polymerization. Then, it hold | maintained at 65 degreeC for 60 minute (s), polymerization of acrylic rubber (A2 ') was completed, and latex of the rubber-like polymer (G-3) was obtained. The polymerization rate of this rubber-like polymer (G-3) was 99.9 mass%.
A graft copolymer 3 was obtained in the same manner as in Example 1 except that this rubbery polymer (G-3) latex was used. A thermoplastic resin composition was obtained in the same manner as in Example 1 except that the graft copolymer 3 was used, and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

(Comparative Example 2)
A thermoplastic resin composition was obtained in the same manner as in Example 1 except that the graft copolymer was not blended, and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[Measurement result of Izod impact strength]
The thermoplastic resin compositions of Examples 1 and 2 containing the graft copolymer of the present invention are substantially equivalent to the impact strength of the thermoplastic resin composition of Comparative Example 1 containing the graft copolymer according to the prior art. The impact resistance was ensured.

[Measurement result of gelation time]
The thermoplastic resin compositions of Examples 1 and 2 containing the graft copolymer of the present invention had a gelation time in the range of 200 seconds to less than 400 seconds. This indicates that the thermal decomposition of the vinyl chloride resin due to a rapid increase in melt viscosity is suppressed, and the productivity at the time of processing the thermoplastic resin composition is excellent. In particular, in Example 2 in which the supply time of the second raw material monomer was increased, the gelation time was longer, indicating that the processability of the thermoplastic resin composition was particularly excellent.
On the other hand, the thermoplasticity of Comparative Example 1 using a rubbery polymer obtained by starting polymerization after adding the second raw material monomer in a batch into a reaction vessel charged with acrylic rubber (A1). In the resin composition, the gelation time was less than 200 seconds and was excessively short. This indicates that when the thermoplastic resin composition is produced, the melt viscosity rapidly increases, the resin temperature during the molding process increases, and the vinyl chloride resin is likely to be thermally decomposed.
The thermoplastic resin composition of Comparative Example 2 containing no graft copolymer did not gel within the measurement time and had low impact strength.

Claims (4)

Acrylic rubber (A1) is produced by emulsion polymerization of the first raw material monomer, and the second raw material monomer is supplied in the range of 5 minutes to 10 hours in the presence of the acrylic rubber (A1). A method for producing a rubbery polymer, which starts emulsion polymerization simultaneously with its supply to produce acrylic rubber (A2),
The first raw material monomer includes (meth) acrylate represented by the following chemical formula (I), the second raw material monomer includes n-butyl acrylate, or the first raw material monomer is n-butyl acrylate is included, and the second raw material monomer includes (meth) acrylate represented by the following chemical formula (I):
Acrylic rubber obtained by emulsion polymerization of a raw material monomer containing n-butyl acrylate having a glass transition temperature of acrylic rubber obtained by emulsion polymerization of a raw material monomer containing (meth) acrylate represented by the following chemical formula (I) A method for producing a rubbery polymer, characterized by being lower than the glass transition temperature of rubber.

(In the chemical formula (I), R ¹ is a hydrogen atom or a methyl group, and R ² is composed of a substituent having a branched chain, an alkylene group having a hydroxyl group or an alkoxyl group at the terminal, and an alkyl group having 12 or more carbon atoms. And at least one substituent selected from the group.)   A rubbery polymer produced by the method for producing a rubbery polymer according to claim 1.   A graft copolymer obtained by graft polymerizing a raw material monomer for grafting to the rubbery polymer according to claim 2.   A thermoplastic resin composition comprising the graft copolymer according to claim 3 and a thermoplastic resin.