Graft copolymer containing polyorganosiloxane, method for producing the same, and resin composition containing the same

Abstract

The present invention relates to a method for producing a graft copolymer containing a polyorganosiloxane, comprising: a step of coating a hard core (A) containing a poly(alkyl (meth)acrylate) with a mixture (b) of polymerization including an organosiloxane monomer (b1), an alkyl (meth)acrylate monomer (b2), and an optional acrylic crosslinking agent (b3), to obtain a composite rubber (B); and a step of graft polymerizing the obtained composite rubber (B) with an alkyl (meth)acrylate (C) to obtain a graft copolymer containing a polyorganosiloxane. The production method according to the present invention can obtain a graft copolymer containing a polyorganosiloxane having a multilayer structure, which can be used as an impact modifier and a color developer, and by adding it to a resin, a resin composition having both excellent impact resistance and color development can be obtained.

Description

Technical Field

[0001] This invention relates to a graft copolymer containing a polyorganosiloxane, a resin composition containing the graft copolymer containing the polyorganosiloxane, and a method for preparing the graft copolymer containing the polyorganosiloxane. Background Technology

[0002] Aromatic polyester resin molded products are widely used in the automotive, office automation, electrical, and electronics industries. To reduce the cost of molded products, it is necessary to color the resin itself to achieve the desired hue while maintaining its original mechanical properties. However, current technology has not yet been able to modify aromatic polyester resins into composite materials that simultaneously possess both excellent color development and impact resistance. Summary of the Invention

[0003] In view of the above facts, the objective of the present invention is to provide a graft copolymer containing a polyorganosiloxane that can achieve both color development and mechanical properties such as impact resistance, a resin composition containing the graft copolymer, and a method for preparing the graft copolymer.

[0004] Solution for solving the problem Through a series of studies, the inventors discovered that by coating a hard core (A) containing poly(meth)acrylate with a mixture (b) comprising organosiloxane monomer (b1), (meth)acrylate monomer (b2), and optionally an acrylic crosslinking agent (b3), a composite rubber (B) is obtained. Furthermore, the obtained composite rubber (B) is grafted with (meth)acrylate (C) to obtain a graft copolymer containing polyorganosiloxane, thereby preparing a graft copolymer containing polyorganosiloxane with good color development and impact resistance.

[0005] A first aspect of the present invention provides a method for preparing a graft copolymer containing a polysiloxane, comprising: a step of coating a hard core (A) containing a poly(meth)acrylate with a mixture (b) comprising an organosiloxane monomer (b1), a (meth)acrylate monomer (b2), and optionally an acrylic crosslinking agent (b3) to obtain a composite rubber (B); and a step of grafting the obtained composite rubber (B) with a (meth)acrylate (C) to obtain a graft copolymer containing a polysiloxane.

[0006] Furthermore, in the first aspect, when the total mass of the graft copolymer containing polyorganosiloxane is set to 100 parts by mass, the content of the hard core (A) of the above-mentioned poly(meth)acrylate is 10 to 40 parts by mass, preferably 15 to 35 parts by mass, and more preferably 20 to 30 parts by mass.

[0007] Furthermore, in the first aspect, when the total mass of the graft copolymer containing the polysiloxane is set to 100 parts by mass, the content of the aforementioned organosiloxane monomer (b1) is 0 to 50 parts by mass, preferably 5 to 40 parts by mass, and more preferably 8 to 30 parts by mass.

[0008] Furthermore, in the first aspect, when the total mass of the graft copolymer containing polyorganosiloxane is set to 100 parts by mass, the content of the above-mentioned alkyl methacrylate monomer (b2) is 10 to 55 parts by mass, preferably 20 to 50 parts by mass, and more preferably 30 to 45 parts by mass.

[0009] Furthermore, in the first aspect, when the total mass of the graft copolymer containing polyorganosiloxane is set to 100 parts by mass, the content of the acrylic crosslinking agent (b3) is 0 to 2 parts by mass, preferably 0.1 to 1 parts by mass, and more preferably 0.2 to 0.5 parts by mass.

[0010] Furthermore, in the first aspect, when the total mass of the graft copolymer containing polyorganosiloxane is set to 100 parts by mass, the content of the above-mentioned alkyl methacrylate (C) is 5 to 50 parts by mass, preferably 10 to 40 parts by mass, and more preferably 20 to 30 parts by mass.

[0011] Furthermore, in the first aspect, the mass average particle size of the hard core (A) of the aforementioned poly(meth)acrylate is 300 to 800 nm.

[0012] Furthermore, in the first aspect, the aforementioned poly(meth)acrylate alkyl ester core (A) is polymerized from (meth)acrylate monomers, optionally aromatic vinyl monomers, and an acrylic crosslinking agent as required, so that the resulting poly(meth)acrylate alkyl ester core (A) has a crosslinked structure.

[0013] Furthermore, in the first aspect, the aforementioned alkyl methacrylate is selected from at least one of alkyl acrylates and alkyl methacrylates having 1-12 alkyl carbon atoms, including but not limited to at least one of methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, hexyl methacrylate, and n-dodecyl methacrylate.

[0014] Furthermore, in the first aspect, the aforementioned aromatic vinyl monomer is selected from at least one of styrene, α-methylstyrene, vinyltoluene, and chlorostyrene.

[0015] Furthermore, in the first aspect, the aforementioned acrylic crosslinking agent is selected from at least one of allyl methacrylate (ALMA), ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, triallyl cyanurate, and triallyl isocyanurate.

[0016] Furthermore, in the first aspect, the aforementioned composite rubber (B) is obtained by coating polymerizing a mixture (b) of organosiloxane monomer (b1), alkyl (meth)acrylate monomer (b2), and optionally an acrylic crosslinking agent (b3) onto the aforementioned poly(alkyl (meth)acrylate) hard core (A) with a desired free radical polymerization initiator.

[0017] Furthermore, in the first aspect, the organosiloxane monomer (b1) is selected from at least one of octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, and decamethylcyclopentasiloxane.

[0018] Furthermore, in the first aspect, the alkyl methacrylate monomer (b2) may be the same as or different from the alkyl methacrylate monomer used to form the core (A) of the above-mentioned poly(alkyl methacrylate), and is preferably selected from at least one of alkyl acrylates and alkyl methacrylates having 1-12 alkyl carbon atoms, including but not limited to at least one of methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, hexyl methacrylate, n-dodecyl methacrylate, etc.

[0019] Furthermore, in the first aspect, the acrylic crosslinking agent (b3) may be the same as or different from the acrylic crosslinking agent used to form the hard core (A) of the above-mentioned poly(meth)acrylate, and is preferably selected from at least one of allyl methacrylate (ALMA), ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, triallyl cyanurate, and triallyl isocyanurate.

[0020] Furthermore, in the first aspect, the polymerization initiator is selected from at least one of inorganic peroxides, organic peroxides, and azo initiators.

[0021] Furthermore, in the first aspect, the aforementioned inorganic peroxide is selected from at least one of hydrogen peroxide, potassium persulfate, and ammonium persulfate.

[0022] Furthermore, in the first aspect, the aforementioned organic peroxide is selected from at least one of dicumyl hydroperoxide, p-menthane hydroperoxide, cumyl hydroperoxide, tert-butyl hydroperoxide, succinic acid peroxide, tert-butyl peroxyneodecanate, tert-butyl peroxyneoheptanoate, tert-butyl peroxyneoplastate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and tert-butyl peroxy-2-ethylhexanoate.

[0023] Furthermore, in the first aspect, the aforementioned azo initiator is selected from at least one of oil-soluble azo initiators and water-soluble azo initiators.

[0024] Furthermore, in the first aspect, when the above-mentioned peroxide is used alone, it can be used in conjunction with a reducing agent or the like as a redox initiator.

[0025] Furthermore, in the first aspect, the reducing agent is selected from at least one of sodium formaldehyde sulfoxylate, L-ascorbic acid, fructose, dextrose, sorbitol, and inositol.

[0026] Furthermore, in the first aspect, the aforementioned redox initiator is a composition comprising the aforementioned inorganic / organic peroxide, the aforementioned reducing agent, and ferrous sulfate-ethylenediaminetetraacetic acid disodium salt.

[0027] Furthermore, in the first aspect, when manufacturing the aforementioned poly(meth)acrylate alkyl ester core (A) or composite rubber (B), the average particle size of the poly(meth)acrylate alkyl ester core (A) and composite rubber (B) can be controlled by adding an emulsifier to stabilize the latex.

[0028] Furthermore, in the first aspect, the emulsifier added to the latex used in manufacturing the aforementioned poly(meth)acrylate alkyl ester core (A) may be the same as or different from the emulsifier used in manufacturing the aforementioned composite rubber (B), and anionic and nonionic emulsifiers are preferred. From the viewpoint of reducing the sulfate content in the polymer, anionic emulsifiers are more preferred.

[0029] Furthermore, in the first aspect, the mass ratio of the aforementioned organosiloxane monomer (b1) to the (meth)acrylate alkyl ester monomer (b2) is 0-10, preferably 0.1-3, and more preferably 0.2-1.

[0030] Furthermore, in the first aspect, the aforementioned alkyl methacrylate (C) comprises (meth)acrylate monomers, and optionally aromatic vinyl monomers and cyano-modified vinyl monomers.

[0031] Furthermore, in the first aspect, the aforementioned (meth)acrylate monomer may be the same as or different from the (meth)acrylate alkyl monomer used to form the core (A) of the aforementioned poly(meth)acrylate alkyl ester, and is preferably selected from at least one of (meth)acrylate methyl methacrylate, (meth)acrylate ethyl methacrylate, (meth)acrylate n-propyl methacrylate, (meth)acrylate isopropyl methacrylate, (meth)acrylate n-butyl methacrylate, (meth)acrylate isobutyl methacrylate, (meth)acrylate tert-butyl methacrylate, and (meth)acrylate-2-ethylhexyl methacrylate.

[0032] Furthermore, in the first aspect, the aforementioned aromatic vinyl monomer is selected from at least one of styrene, α-methylstyrene, vinyltoluene, and chlorostyrene.

[0033] Furthermore, in the first aspect, the aforementioned cyano-vinyl monomer is selected from at least one of acrylonitrile and methacrylonitrile.

[0034] Furthermore, in the first aspect, at least a portion of the aforementioned alkyl methacrylate (C) is grafted and polymerized with the aforementioned composite rubber (B) to form a graft copolymer.

[0035] Furthermore, in the first aspect, the aforementioned graft polymerization is a primary or multi-level polymerization.

[0036] Furthermore, in the first aspect, the aforementioned multi-stage polymerization involves adding the aforementioned alkyl methacrylate (C) to the aforementioned composite rubber (B) in several stages or continuously.

[0037] Furthermore, a second aspect of the present invention provides a graft copolymer containing polyorganosiloxane obtained by the preparation method described in the first aspect, wherein the graft copolymer containing polyorganosiloxane has a multi-layer core-shell structure, preferably a three-layer core-shell structure, and the boundaries of each layer are clearly defined.

[0038] A third aspect of the present invention provides a resin composition comprising the graft copolymer containing polyorganosiloxane as described in the second aspect and a resin.

[0039] Furthermore, in the third aspect, when the total weight of the resin composition is set to 100 parts by mass, the content of the above-mentioned graft copolymer containing polyorganosiloxane is 1-10 parts by mass, preferably 3-8 parts by mass.

[0040] Furthermore, in the third aspect, the resin is selected from one of polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), polymethyl methacrylate (PMMA), and styrene-acrylonitrile copolymer (AS) resins.

[0041] Furthermore, in the third aspect, the aforementioned resin composition further contains a colorant.

[0042] Invention Effects According to the present invention, a method for preparing a graft copolymer containing polyorganosiloxane is provided. This method copolymerizes a siloxane-containing composite rubber (B) and an alkyl (meth)acrylate (C) into a graft copolymer containing polyorganosiloxane that exhibits good color development and impact resistance. Furthermore, when the graft copolymer containing polyorganosiloxane obtained by the above preparation method is mixed with resins such as polycarbonate and ABS, a resin composition with excellent color development and impact resistance can be obtained. The resin composition of the present invention can be widely used in electronic and electrical appliances and industrial machinery parts. Detailed Implementation

[0043] First, the preparation method of the graft copolymer containing polyorganosiloxane of the present invention will be described.

[0044] The method for preparing the graft copolymer containing polyorganosiloxane of the present invention includes: a step of coating and polymerizing a mixture (b) comprising an organosiloxane monomer (b1), an (meth)acrylate monomer (b2), and an optional acrylic crosslinking agent (b3) onto a hard core (A) containing poly(meth)acrylate to obtain a composite rubber (B); and a step of graft polymerizing the obtained composite rubber (B) with an (meth)acrylate alkyl ester (C) to obtain a graft copolymer containing polyorganosiloxane.

[0045] The term "coating polymerization" as used herein refers to the simultaneous polymerization of organosiloxane monomers (b1), (meth)acrylate alkyl ester monomers (b2), and optionally an acrylic crosslinking agent (b3) with a hard core (A) containing poly(meth)acrylate alkyl ester, thereby forming a polymer coating the hard core (A) containing poly(meth)acrylate alkyl ester. This results in a composite rubber (B) with a structure of a hard core and a soft rubber coating layer on the surface of the core. Graft polymerization of composite rubber (B) with (meth)acrylate alkyl ester (C) further coats the surface of the soft rubber layer with a hard outer shell, thus forming a graft copolymer containing polyorganosiloxane.

[0046] As can be seen, the preparation method according to the present invention can yield a multilayered graft copolymer, which can be used as both an impact modifier and a colorant. Adding it to a resin can produce a resin composition with both excellent impact resistance and color development. The aforementioned multilayered structure refers to polymer particles composed of a hard core, a soft intermediate layer, and a hard outer shell. The hard core is mainly formed by a hard core (A) containing poly(meth)acrylate alkyl esters. The soft intermediate layer is mainly polymerized from organosiloxane monomers (b1), (meth)acrylate alkyl ester monomers (b2), and optionally an acrylic crosslinking agent (b3). The hard outer shell is mainly formed from (meth)acrylate alkyl esters (C). The core, intermediate layer, and outer shell each possess different properties and have different effects on the matrix resin. Generally, the core possesses most of the properties of the polymer particle itself; the intermediate layer connects the inner layer and the outer shell, enhancing interlayer bonding; and the outer shell plays a synergistic role, facilitating particle dispersion in the matrix resin.

[0047] In the preparation method of the graft copolymer containing polyorganosiloxane of the present invention, when the mass of the graft copolymer containing polyorganosiloxane is set to 100 parts by mass, the amount of hard core (A) containing poly(meth)acrylate is added to 10 to 40 parts by mass, preferably 15 to 35 parts by mass, and more preferably 20 to 30 parts by mass.

[0048] The amount of organosiloxane monomer (b1) added is 0 to 50 parts by weight, preferably 5 to 40 parts by weight, and more preferably 8 to 30 parts by weight.

[0049] The amount of (meth)acrylate alkyl ester monomer (b2) added is 10 to 55 parts by weight, preferably 20 to 50 parts by weight, and more preferably 30 to 45 parts by weight.

[0050] The amount of acrylic crosslinking agent (b3) added is 0 to 2 parts by weight, preferably 0.1 to 1 parts by weight, and more preferably 0.2 to 0.5 parts by weight.

[0051] The amount of (meth)acrylate alkyl ester (C) added is 5 to 50 parts by weight, preferably 10 to 40 parts by weight, and more preferably 20 to 30 parts by weight.

[0052] The hard core (A) containing poly(meth)acrylate is obtained by polymerization of (meth)acrylate monomers, optional aromatic vinyl monomers and optional acrylic crosslinking agents in the presence of an initiator and emulsifier as desired.

[0053] Alkyl methacrylates include methyl methacrylate (such as MMA, MA), ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, hexyl methacrylate, and n-dodecyl methacrylate. From the perspective of improving the impact resistance and gloss of the resulting molded article, methyl methacrylate (MMA), methyl acrylate (MA), and n-butyl acrylate (BA) are preferred.

[0054] Aromatic vinyl monomers include styrene, α-methylstyrene, vinyltoluene, and chlorostyrene. These monomers can be used alone or in combination of two or more.

[0055] Acrylic crosslinking agents are components that introduce crosslinking structures into the hard core (A) of poly(meth)acrylate alkyl esters. They also function as grafting crossover points for the encapsulation polymerization of organosiloxane monomers (b1) and (meth)acrylate alkyl ester monomers (b2), which will be described later. Examples of acrylic crosslinking agents include allyl methacrylate (ALMA), ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, triallyl cyanurate, and triallyl isocyanurate. These acrylic crosslinking agents can be used alone or in combination of two or more.

[0056] In the step of preparing the hard core (A), in order to stabilize the system, it is necessary to control the average particle size of the hard core (A), which can be achieved by adding an emulsifier.

[0057] Anionic emulsifiers and nonionic emulsifiers can be listed as emulsifiers, with anionic emulsifiers being preferred.

[0058] Examples of anionic emulsifiers include, but are not limited to, sodium dodecyl sulfate (SDS), sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium stearate, sodium oleate, sodium dioctyl sulfosuccinate, and sodium dihexyl sulfosuccinate.

[0059] Examples of nonionic emulsifiers include, but are not limited to, fatty alcohol polyoxyethylene ethers, polyethylene glycol fatty acid esters, glyceryl stearate, and monoglyceride fatty acid esters.

[0060] At least one of inorganic peroxides, organic peroxides, and azo initiators can be listed as initiators.

[0061] Examples of inorganic peroxides include hydrogen peroxide, potassium persulfate, and ammonium persulfate. These inorganic peroxides can be used individually or in combination of two or more.

[0062] Examples of organic peroxides include dicumyl hydroperoxide, p-menthane hydroperoxide, isocumyl hydroperoxide, tert-butyl hydroperoxide, succinic acid peroxide, tert-butyl peroxyneodecanate, tert-butyl peroxyneoheptanoate, tert-butyl peroxyneopentanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and tert-butyl peroxy-2-ethylhexanoate. These organic peroxides can be used individually or in combination of two or more.

[0063] As azo initiators, oil-soluble azo initiators and water-soluble azo initiators can be listed. These azo initiators can be used alone or in combination of two or more.

[0064] When the total mass of the monomers forming the hard core (A) is set to 100 parts by mass, the amount of crosslinking agent added is 0.1 to 5 parts by mass, preferably 0.5 to 3 parts by mass, more preferably 1 to 2 parts by mass; the amount of initiator added is 0.1 to 5 parts by mass, preferably 0.5 to 3 parts by mass, more preferably 1 to 2 parts by mass; and the amount of emulsifier added is 0.1 to 10 parts by mass, preferably 1 to 8 parts by mass, more preferably 3 to 5 parts by mass.

[0065] The steps for coating polymerization to form composite rubber (B) can be exemplified by adding a mixture (b) of organosiloxane monomer (b1), (meth)acrylate monomer (b2), and optional acrylic crosslinking agent (b3) to a system of poly(alkyl methacrylate) core (A), and polymerizing using a known free radical polymerization initiator and emulsifier to obtain a latex of composite rubber (B). Methods for preparing a mixture (b) by adding (meth)acrylate monomer (b2) and optional acrylic crosslinking agent (b3) to the latex of organosiloxane monomer (b1) can be exemplified by adding the (meth)acrylate monomer (b2) and optional acrylic crosslinking agent (b3) components to the latex of organosiloxane monomer (b1) in a single step, or by adding the (meth)acrylate monomer (b2) and optional acrylic crosslinking agent (b3) components dropwise to the latex of organosiloxane monomer (b1) at a fixed rate. From the perspective of improving the impact resistance of the obtained molded article, it is preferable to add the (meth)acrylate alkyl ester monomer (b2) component and the optional acrylic crosslinking agent (b3) component to the latex of organosiloxane monomer (b1) in one step.

[0066] The mass ratio of organosiloxane monomer (b1) to (meth)acrylate alkyl ester monomer (b2) is 0-10, preferably 0.1-3, and more preferably 0.2-1. When the mass ratio of organosiloxane monomer (b1) to alkyl acrylate monomer (b2) is 0.1-3, the resulting molded article has good impact resistance and the pigment colorability does not decrease.

[0067] Acrylic crosslinking agent (b3) is a component that introduces a crosslinked structure into the composite rubber (B), and also functions as a grafting crossover point for the graft polymerization of the alkyl methacrylate (C) described later. Examples of crosslinking agents include allyl methacrylate (ALMA), ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, triallyl cyanurate, and triallyl isocyanurate. These crosslinking agents can be used alone or in combination of two or more.

[0068] When the total mass (i.e. the mass of mixture (b)) of the organosiloxane monomer (b1), the (meth)acrylate alkyl ester monomer (b2) and the optional acrylic crosslinking agent (b3) is set to 100 parts by mass, the amount of crosslinking agent added is 0 to 3 parts by mass, preferably 0.1 to 1.5 parts by mass, and more preferably 0.2 to 0.5 parts by mass.

[0069] When preparing the composite rubber (B), the mass ratio of the hard core (A) to the mixture (b) is 0.1-5, preferably 0.2-1, and more preferably 0.3-0.7.

[0070] As the free radical polymerization initiator and emulsifier in the step of forming the composite rubber (B), the same or different initiators and emulsifiers as those in the step of preparing the hard core (A) can be used.

[0071] For example, at least one of inorganic peroxides, organic peroxides, and azo initiators can be listed as free radical polymerization initiators.

[0072] Examples of inorganic peroxides include hydrogen peroxide, potassium persulfate, and ammonium persulfate. These inorganic peroxides can be used individually or in combination of two or more.

[0073] Examples of organic peroxides include dicumyl hydroperoxide, p-menthane hydroperoxide, isocumyl hydroperoxide, tert-butyl hydroperoxide, succinic acid peroxide, tert-butyl peroxyneodecanate, tert-butyl peroxyneoheptanoate, tert-butyl peroxyneopentanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and tert-butyl peroxy-2-ethylhexanoate. These organic peroxides can be used individually or in combination of two or more.

[0074] As azo initiators, oil-soluble azo initiators and water-soluble azo initiators can be listed. These azo initiators can be used alone or in combination of two or more.

[0075] When the total mass of the organosiloxane monomer (b1), the (meth)acrylate alkyl ester monomer (b2), and the optional acrylic crosslinking agent (b3) (i.e., the mass of mixture (b)) is set to 100 parts by mass, the amount of polymerization initiator added is 0.1 to 5 parts by mass, preferably 0.2 to 3 parts by mass, and more preferably 0.5 to 1.5 parts by mass.

[0076] When the above peroxides are used alone, they can be used in conjunction with reducing agents as redox initiators.

[0077] Examples of reducing agents include sodium formaldehyde sulfoxylate, L-ascorbic acid, fructose, dextrose, sorbitol, and inositol. These reducing agents can be used alone or in combination of two or more. Furthermore, when using sodium formaldehyde sulfoxylate as a reducing agent, it is preferable to minimize the amount used, from the viewpoint of reducing the amount of sulfate in the powder.

[0078] The redox initiator is a composition comprising the above-mentioned inorganic / organic peroxide, the above-mentioned reducing agent, and ferrous sulfate-ethylenediaminetetraacetic acid disodium salt.

[0079] In the process of coating and polymerizing the latex to form the composite rubber (B), it is necessary to control the average particle size of the composite rubber in order to stabilize the latex, which can be achieved by adding an emulsifier.

[0080] Anionic and nonionic emulsifiers can be cited as examples of emulsifiers. From the viewpoint of reducing the amount of sulfate in powders, anionic emulsifiers are preferred.

[0081] Examples of anionic emulsifiers include, but are not limited to, sodium dodecyl sulfate (SDS), sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium stearate, sodium oleate, sodium dioctyl sulfosuccinate, and sodium dihexyl sulfosuccinate.

[0082] Examples of nonionic emulsifiers include, but are not limited to, fatty alcohol polyoxyethylene ethers, polyethylene glycol fatty acid esters, glyceryl stearate, and monoglyceride fatty acid esters.

[0083] When the total mass of the organosiloxane monomer (b1), the (meth)acrylate alkyl ester monomer (b2), and the optional acrylic crosslinking agent (b3) (i.e., the mass of mixture (b)) is set to 100 parts by mass, the amount of emulsifier added is 0.1 to 10 parts by mass, preferably 0.5 to 5 parts by mass, and more preferably 1 to 3 parts by mass.

[0084] In the step of grafting the obtained composite rubber (B) with alkyl methacrylate (C) to obtain a graft copolymer containing polyorganosiloxane, the alkyl methacrylate (C) includes alkyl methacrylate monomers, and optionally aromatic vinyl monomers and cyano-modified vinyl monomers.

[0085] The (meth)acrylate monomer and the (meth)acrylate alkyl ester monomer forming the hard core (A) may be the same or different, and may include at least one of (meth)acrylate, (meth)acrylate, (meth)acrylate n-propyl acrylate, (meth)acrylate isopropyl acrylate, (meth)acrylate n-butyl acrylate, (meth)acrylate isobutyl acrylate, (meth)acrylate tert-butyl acrylate, and (meth)acrylate-2-ethylhexyl acrylate.

[0086] Aromatic vinyl monomers include styrene, α-methylstyrene, vinyltoluene, and chlorostyrene.

[0087] Examples of cyano-modified vinyl monomers include acrylonitrile and methacrylonitrile.

[0088] These monomers can be used alone or in combination of two or more.

[0089] In preparing the graft copolymer containing polyorganosiloxane, the mass ratio of composite rubber (B) to alkyl methacrylate (C) is 0.1-20, preferably 1-10, and more preferably 2-6.

[0090] The polymerization methods for grafted (meth)acrylate (C) can be exemplified by adding the graft monomer (meth)acrylate (C) to the composite rubber (B) latex and carrying out primary or multi-stage polymerization.

[0091] Multi-stage polymerization can be exemplified by adding graft monomers (meth)acrylates (C) in stages or continuously in the presence of a composite rubber (B) latex. This polymerization method yields good polymerization stability and can stably produce latexes with the desired particle size and distribution.

[0092] The determination of each physical property in this invention is carried out by the following method.

[0093] (1) Impact strength Impact strength was tested according to ASTM D-256 standard using an Izod test bar with a notch, and measured in kilojoules per square meter (kJ / m²). 2 )express.

[0094] (2) Conversion rate The latex-like graft copolymer was dried in a hot air drying oven at 105℃ for 2 hours. The remaining solids were weighed and calculated as 100 × solids content / monomer content.

[0095] (3) Coloring properties According to GB / T13451.2-92, the determination of the relative tinting strength of color pigments and the relative scattering strength of white pigments.

[0096] (4) Average particle size Based on the principle of dynamic scattering light, measurements were performed using a Brookhaven 90Plus high-sensitivity Zeta potential and particle size analyzer.

[0097] Example The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the materials and methods involved in the embodiments are all materials and methods commonly used in the art. In addition, regarding "parts" and "%" in this specification, unless otherwise specified, they respectively represent "parts by mass" and "% by mass".

[0098] 1. Preparation of graft copolymers Examples 1-5 (1) Add 250 parts of deionized water and 1 part of anionic emulsifier sodium dodecyl sulfate (SDS) to a reactor equipped with a stirrer, reflux condenser, nitrogen inlet, thermometer, and monomer dropper. Under nitrogen protection, add 0.3 parts of a 10% aqueous solution of initiator KPS (potassium persulfate), methyl methacrylate (MMA), methyl acrylate (MA), and allyl methacrylate (ALMA) in the amounts shown in Table 1. Raise the temperature of the reaction mixture to 80°C and maintain it at that temperature for 60 minutes. A latex with a hard core (A) of poly(meth)acrylate (as the innermost layer) is obtained, with an average particle size of 350 nm.

[0099] (2) Add 0.5 parts of initiator KPS to the latex of the innermost hard core (A) obtained in step (1), and then dropwise add the mixture of n-butyl acrylate monomer (BA), allyl methacrylate (ALMA) and octamethylcyclotetrasiloxane (D4) contained in Table 1 (b) over 60 minutes. During the dropwise addition, add 1 part of anionic emulsifier sodium dodecyl sulfate (SDS). After the dropwise addition is completed, keep stirring for 60 minutes. The latex of composite rubber (B) is thus obtained, wherein the composite rubber (B) has a double-layer structure, namely: the innermost layer is the hard core (A), and the outer layer of the hard core (A) is coated with a soft rubber coating layer.

[0100] (3) Add 0.2 parts of initiator KPS to the latex of the composite rubber (B) with a bilayer structure obtained in step (2), and add the mixture of components (C) in Table 1 dropwise over 30 minutes. After the dropwise addition is completed, continue stirring the entire system for 60 minutes to obtain a graft copolymer containing polyorganosiloxane, which has a three-layer structure, namely: a hard outer shell is grafted onto the outer layer of the bilayer structure of the composite rubber (B).

[0101] (4) After the system is stabilized, the graft copolymer containing polyorganosiloxane is diluted with ion-exchanged water to a solid content of 15%, and 2 parts of 5% magnesium sulfate aqueous solution with a solid content is added to obtain a coagulated slurry. The slurry is heated to 95°C and held for 30 minutes, then cooled to 40°C and dehydrated to obtain powder or granular graft copolymer containing polyorganosiloxane, which are represented by the numbers AT-1 to AT-5 respectively.

[0102] In Table 1, MMA represents methyl methacrylate, MA represents methyl acrylate, ALMA represents allyl methacrylate, an acrylic crosslinking agent, BA represents n-butyl acrylate (used as b2), and D4 represents octamethylcyclotetrasiloxane (used as b1). All of these are monomers.

[0103] Table 1 2. Performance test results of applying the grafted polymers obtained in Examples 6-12 and Comparative Examples 1-4 to the resin. The graft copolymers AT-1 to AT-5 obtained in Examples 1-5 were used, along with polycarbonate resins (PC-1: Teijin Polycarbonate Co., Ltd. L-1225Y; PC-2: Teijin Polycarbonate Co., Ltd. L-1225L). The mixtures were prepared according to the weight parts shown in Table 2. The resulting mixtures were melt-blended at 270°C using a twin-screw extruder (Jente Electromechanical Co., Ltd. SHJ-36) to produce granules. These granules were then used to form injection molded particles (Haitian Plastics Machinery Group Co., Ltd. SA860 / 260). The resulting particles were used for performance evaluation. The results are shown in Table 2.

[0104] In Comparative Examples 3 and 4, Mitsubishi S-2001 product was mixed with PC-1 and PC-2 respectively, and granules were prepared according to the above method.

[0105] Table 2 As shown in Table 2, the grafted polymer of the present invention can simultaneously improve the colorability and impact resistance of polycarbonate resin.

[0106] The above embodiments are preferred embodiments of the present invention. However, the present invention is not limited to these embodiments. Any changes, modifications, substitutions, combinations, or simplifications made to the above embodiments without departing from the spirit and principle of the present invention are considered equivalent substitution methods and are included within the protection scope of the present invention.

[0107] Industrial availability The graft copolymers containing polyorganosiloxanes involved in this invention can be mixed with resins such as PC to prepare resin compositions with excellent impact resistance and color development. The resin compositions of this invention can be widely used in electronic and electrical appliances and industrial machinery parts.

Claims

1. A method for preparing a graft copolymer containing a polyorganosiloxane, characterized in that, include: The step of coating a hard core (A) containing poly(alkyl methacrylate) with a mixture (b) comprising an organosiloxane monomer (b1), an alkyl (meth)acrylate monomer (b2), and optionally an acrylic crosslinking agent (b3) to obtain a composite rubber (B); and The step involves grafting the obtained composite rubber (B) with alkyl (meth)acrylate (C) to obtain a graft copolymer containing polyorganosiloxane.

2. The preparation method according to claim 1, characterized in that: in, Based on the total weight of the graft copolymer containing polyorganosiloxane as 100 parts by mass, the content of the poly(meth)acrylate alkyl ester core (A) is 10-40 parts by mass (preferably 15-35 parts by mass, more preferably 20-30 parts by mass); the content of the organosiloxane monomer (b1) is 0-50 parts by mass (preferably 5-40 parts by mass, more preferably 8-30 parts by mass); the content of the (meth)acrylate alkyl ester monomer (b2) is 10-55 parts by mass (preferably 20-50 parts by mass, more preferably 30-45 parts by mass); the content of the acrylic crosslinking agent (b3) is 0-2 parts by mass (preferably 0.1-1 parts by mass, more preferably 0.2-0.5 parts by mass); and the content of the (meth)acrylate alkyl ester (C) is 5-50 parts by mass (preferably 10-40 parts by mass, more preferably 20-30 parts by mass).

3. The preparation method according to claim 1 or 2, characterized in that: The mass-average particle size of the hard core (A) of the poly(meth)acrylate is 300-800 nm.

4. The preparation method according to any one of claims 1-3, characterized in that: The hard core (A) of the poly(meth)acrylate is obtained by polymerization of (meth)acrylate, optional aromatic vinyl monomers, and acrylic crosslinking agents, initiators and emulsifiers as needed.

5. The preparation method according to claim 4, characterized in that: The alkyl methacrylate is selected from at least one of alkyl acrylates and alkyl methacrylates having 1-12 alkyl carbon atoms, such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, hexyl methacrylate, and n-dodecyl methacrylate.

6. The preparation method according to claim 4, characterized in that: The aromatic vinyl monomer is selected from at least one of styrene, α-methylstyrene, vinyltoluene, and chlorostyrene.

7. The preparation method according to any one of claims 1-6, characterized in that: The composite rubber (B) is obtained by polymerization of a hard core (A) of poly(meth)acrylate alkyl ester, a mixture (b) of organosiloxane monomer (b1), (meth)acrylate alkyl ester monomer (b2), and optional acrylic crosslinking agent (b3), and an initiator and emulsifier as needed.

8. The preparation method according to any one of claims 4-7, characterized in that: The acrylic crosslinking agent is selected from at least one of allyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, triallyl cyanurate, and triallyl isocyanurate.

9. The preparation method according to any one of claims 4-8, characterized in that: The emulsifier is selected from at least one of anionic emulsifiers and nonionic emulsifiers.

10. The preparation method according to any one of claims 1-9, characterized in that: The graft copolymer containing polyorganosiloxane is obtained by graft polymerization of composite rubber (B) and (meth)acrylate alkyl ester (C) and an initiator as needed; Preferably, the (meth)acrylate (C) comprises (meth)acrylate monomers, and optionally aromatic vinyl monomers and cyano-modified vinyl monomers; More preferably, the (meth)acrylate monomer is selected from at least one of methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. More preferably, the aromatic vinyl monomer is selected from at least one of styrene, α-methylstyrene, vinyltoluene, and chlorostyrene; More preferably, the cyano-vinyl monomer is selected from at least one of acrylonitrile and methacrylonitrile.

11. The preparation method according to any one of claims 4-10, characterized in that: The initiator is selected from at least one of inorganic peroxides, organic peroxides, and azo initiators; preferably, the inorganic peroxide is selected from at least one of hydrogen peroxide, potassium persulfate, and ammonium persulfate; the organic peroxide is selected from at least one of dicumyl hydroperoxide, hydroperoxide-p-menthane, hydroperoxide-isocumyl, tert-butyl hydroperoxide, succinic acid peroxide, tert-butyl peroxyneodecanate, tert-butyl peroxyneoheptanoate, tert-butyl peroxyneoplastate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and tert-butyl peroxy-2-ethylhexanoate; the azo initiator is selected from at least one of oil-soluble azo initiators and water-soluble azo initiators.

12. A graft copolymer containing polyorganosiloxane obtained by the preparation method according to any one of claims 1-11, characterized in that: Its impact resistance is at least 56 KJ / m 2 Preferably 60-75 KJ / m 2 ; Its colorfastness is at least 99.5%.

13. A resin composition, characterized in that: The graft copolymer and resin containing the polyorganosiloxane as described in claim 12.

14. The resin composition according to claim 13, characterized in that: The total weight of the resin composition is 100 parts by weight, and the content of the graft copolymer containing polyorganosiloxane is 1-10 parts by weight, preferably 3-8 parts by weight.

15. The resin composition according to claim 13 or 14, characterized in that: The resin is selected from at least one of polycarbonate, acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, and styrene-acrylonitrile copolymer.

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