CN107880427B

CN107880427B - Rubber modified resin composition and preparation method thereof

Info

Publication number: CN107880427B
Application number: CN201710793869.XA
Authority: CN
Inventors: 黄世玮; 苏文义
Original assignee: Chi Mei Corp
Current assignee: Chi Mei Corp
Priority date: 2016-09-30
Filing date: 2017-09-06
Publication date: 2020-04-14
Anticipated expiration: 2037-09-06
Also published as: TWI604008B; CN107880427A; TW201811902A

Abstract

本发明涉及一种橡胶改性树脂组成物及其制备方法，所述橡胶改性树脂组成物包括苯乙烯‑丙烯腈系共聚物(A)所形成的连续相、丙烯酸酯系橡胶接枝共聚物(B)所形成的分散相以及对孟烷，其中对孟烷的含量大于5ppm且小于180ppm，以及橡胶改性树脂组成物不含苯乙酮。本发明的橡胶改性树脂组成物完全无苯乙酮残留，且具有良好的耐冲击性、耐热性及表面光泽度。The invention relates to a rubber-modified resin composition and a preparation method thereof. The rubber-modified resin composition comprises a continuous phase formed by a styrene-acrylonitrile copolymer (A), an acrylate-based rubber graft copolymer (B) The formed dispersed phase and p-menan, wherein the content of p-menan is more than 5 ppm and less than 180 ppm, and the rubber-modified resin composition does not contain acetophenone. The rubber-modified resin composition of the present invention has no acetophenone residue at all, and has good impact resistance, heat resistance and surface gloss.

Description

Rubber modified resin composition and preparation method thereof

Technical Field

The invention relates to a resin composition, in particular to a rubber modified resin composition and a preparation method thereof.

Background

In general, most of components contained in plastic molded articles used for electric appliances, household goods, and the like are rubber-modified styrene resins, polycarbonate resins (polycarbonate resins), rubber-modified methacrylate resins, and the like. The rubber-modified styrene resin is classified into a butadiene rubber-modified styrene resin and an acrylate rubber-modified styrene resin. The acrylate rubber modified styrene resin is a ternary graft copolymer composed of acrylonitrile, styrene and acrylate rubber. Compared with butadiene rubber modified styrene resin, the acrylate rubber modified styrene resin has greatly improved weather resistance, i.e., is not easy to crack under irradiation of light or heating, because the acrylate rubber with low double bond content is used to replace butadiene rubber. Further, since the weather resistance of the acrylate rubber-modified styrene-based resin is greatly improved as compared with that of the butadiene rubber-modified styrene-based resin, it can be used outdoors as it is. Acrylate rubber-modified styrenic resins are generally used in the automotive field (e.g., outdoor components such as exterior mirrors, radiator grilles, tail fenders, lamp covers, etc.); or applied to the electronic and electrical field (such as all-weather shells of sewing machines, telephones, kitchen equipment, satellite antennas and the like); or applied to the building field and the like.

However, in the existing preparation method, acetophenone (acetophenone) which can generate odor is easy to remain in the acrylate rubber modified styrene resin, which not only causes discomfort to human body, but also limits the applicability of the resin. Therefore, it has become an urgent subject to be studied in the industry to prepare an acrylate rubber-modified styrene resin which is completely free from acetophenone and maintains physical properties required for industrial processing.

Disclosure of Invention

The present invention provides a rubber-modified resin composition which is completely free from acetophenone residues and has excellent impact resistance, heat resistance and surface gloss, and a method for producing the same.

The rubber modified resin composition comprises a continuous phase formed by a styrene-acrylonitrile copolymer (A), a dispersed phase formed by an acrylate rubber graft copolymer (B) and p-menthane, wherein the content of the p-menthane is more than 5ppm and less than 180ppm, and the rubber modified resin composition does not contain acetophenone, namely the content of the acetophenone is less than 1 ppm.

In one embodiment of the present invention, the content of p-menthane is more than 8ppm and less than 150 ppm.

In an embodiment of the present invention, the content of the styrene-acrylonitrile copolymer (a) is 40 to 90 wt% and the content of the acrylate rubber graft copolymer (B) is 10 to 60 wt%, based on 100 wt% of the total weight of the styrene-acrylonitrile copolymer (a) and the acrylate rubber graft copolymer (B).

In one embodiment of the present invention, the rubber modified resin composition comprises, based on 100 wt% of the total weight of the styrene-acrylonitrile copolymer (a) and the acrylate rubber graft copolymer (B): 15 to 25 wt% of acrylonitrile monomer units, 55 to 65 wt% of styrene monomer units and 15 to 25 wt% of acrylate monomer units.

In an embodiment of the present invention, the weight average particle diameter of the acrylate-based rubber graft copolymer (B) is in a monomodal distribution between 0.05 μm and 0.22 μm, a monomodal distribution between 0.26 μm and 0.55 μm, or a bimodal distribution between 0.05 μm and 0.22 μm and between 0.26 μm and 0.55 μm.

The preparation method of the rubber modified resin composition comprises the following steps. A styrene-acrylonitrile copolymer (A) and an acrylate rubber graft copolymer (B) are provided. The styrene-acrylonitrile copolymer (A) and the acrylate rubber graft copolymer (B) are kneaded, wherein the rubber modified resin composition contains p-menthane, the content of the p-menthane is more than 5ppm and less than 180ppm, and the rubber modified resin composition does not contain acetophenone.

In an embodiment of the present invention, the method for providing the acrylate-based rubber graft copolymer (B) includes the following steps. The acrylate-based monomer is subjected to emulsion polymerization to form an acrylate-based rubber emulsion. Subjecting the acrylate-based rubber emulsion to a graft polymerization reaction, wherein the graft polymerization reaction comprises using p-menthane hydroperoxide as an initiator.

In an embodiment of the present invention, the total usage amount of the p-menthane peroxide is less than 1.3 parts by weight and more than 0.35 part by weight based on 100 parts by weight of the dry weight of the acrylate-based rubber emulsion.

In an embodiment of the present invention, the emulsion polymerization reaction includes using p-menthane peroxide as an initiator, wherein the total usage amount of p-menthane peroxide in the emulsion polymerization reaction is less than 1 part by weight and more than 0.05 part by weight based on 100 parts by weight of acrylate monomers.

In view of the above, the rubber-modified resin composition of the present invention includes the styrene-acrylonitrile copolymer (a), the acrylate-based rubber graft copolymer (B), and the p-menthane having a specific content range, but does not contain acetophenone, thereby not only solving the problem of odor caused by acetophenone residue, but also further improving the odor by the p-menthane containing one of the perfume raw materials. Thus, the rubber modified resin composition of the invention has good applicability. In addition, the rubber modified resin composition of the present invention has good impact resistance, heat resistance and surface gloss at the same time by including the styrene-acrylonitrile copolymer (a), the acrylate rubber graft copolymer (B) and the p-menthane having a specific content range.

In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanied with figures are described in detail below.

Detailed Description

In this context, a range denoted by "a numerical value to another numerical value" is a general expression avoiding a recitation of all numerical values in the range in the specification. Thus, recitation of a range of values herein is intended to encompass any value within the range and any smaller range defined by any value within the range, as if the range and smaller range were explicitly recited in the specification.

Herein, the monomer unit means a structural unit formed by polymerization of a monomer.

The rubber modified resin composition provided by one embodiment of the invention comprises a continuous phase formed by a styrene-acrylonitrile copolymer (A), a dispersed phase formed by an acrylate rubber graft copolymer (B) and p-menthane, but does not contain acetophenone, wherein the content of the p-menthane is more than 5ppm and less than 180ppm based on the total weight of the rubber modified resin composition. In this way, the rubber-modified resin composition of the present embodiment not only solves the problem of acetophenone residues, but also further improves the odor by containing p-menthane, thereby improving the applicability thereof. On the other hand, the rubber-modified resin composition of the present embodiment has good impact resistance, heat resistance and surface gloss at the same time by including the styrene-acrylonitrile copolymer (a), the acrylate-based rubber graft copolymer (B) and p-menthane in a specific content range.

If the content of the p-menthane is more than or equal to 180ppm, the flowability of the rubber modified resin composition is poor, and the subsequent processing and forming are influenced; if the amount of p-menthane is less than or equal to 5ppm, the physical properties of the rubber-modified resin composition, such as impact resistance, heat resistance and surface gloss, will be affected, and the standards required in the industry cannot be met. In one embodiment, the amount of p-menthane is preferably more than 8ppm and less than 150ppm, more preferably more than 10ppm and less than 100ppm, and most preferably more than 10ppm and less than 80 ppm.

In the present embodiment, the content of the styrene-acrylonitrile copolymer (a) is 40 to 90% by weight and the content of the acrylate rubber graft copolymer (B) is 10 to 60% by weight, based on 100% by weight of the total weight of the styrene-acrylonitrile copolymer (a) and the acrylate rubber graft copolymer (B). From another perspective, the rubber modified resin composition comprises 15 to 25 wt% of acrylonitrile monomer units, 55 to 65 wt% of styrene monomer units, and 15 to 25 wt% of acrylate monomer units, based on 100 wt% of the total weight of the styrene-acrylonitrile copolymer (a) and the acrylate rubber graft copolymer (B). Here, the acrylate monomer unit, the styrene monomer unit, and the acrylonitrile monomer unit refer to structural units formed by polymerization of an acrylate monomer, a styrene monomer, and an acrylonitrile monomer, respectively.

In detail, in the present embodiment, the styrene-acrylonitrile copolymer (a) is obtained by polymerizing styrene monomers and acrylonitrile monomers, wherein the composition of the styrene-acrylonitrile copolymer (a) comprises 60 to 85 wt% of styrene monomer units and 15 to 40 wt% of acrylonitrile monomer units, preferably 64 to 78 wt% of styrene monomer units and 22 to 36 wt% of acrylonitrile monomer units, the monomer units refer to residues (i.e., residual structures) in polymer molecules obtained by polymerizing the monomers, and specific examples of the styrene monomers include, but are not limited to, styrene, α -methyl styrene, p-t-butyl styrene, p-methyl styrene, o-methyl styrene, m-methyl styrene, 2, 4-dimethyl styrene, ethyl styrene, α -methyl-p-methyl styrene or bromostyrene, etc., wherein styrene or α -methyl styrene is preferred, and specific examples of the acrylonitrile monomers include, but are not limited to, α or α -methyl acrylonitrile, etc., wherein preferably, acrylonitrile, and acrylonitrile, etc.

The polymerization reaction can be carried out by a bulk polymerization method, a solution polymerization method, a suspension polymerization method or an emulsion polymerization method, and among them, a bulk polymerization method or a solution polymerization method is preferable. Taking the solution polymerization as an example, the preparation method of the styrene-acrylonitrile copolymer (A) comprises the step of performing the solution polymerization of the styrene monomer, the acrylonitrile monomer and the polymerization initiator in the presence of the solvent, wherein the operation temperature is preferably in the range of 70 ℃ to 140 ℃, more preferably 90 ℃ to 130 ℃. Examples of the solvent used include toluene, ethylbenzene, methyl ethyl ketone, and the like.

The polymerization initiator includes (but is not limited to): hydrogen peroxide (hydroperoxide) type compounds, for example: tert-butyl peroxide (tert-butyl hydroperoxide), p-menthane hydroperoxide (paramenthane hydroperoxide), and the like; peroxyketals (peroxyketals) compounds, such as: 1, 1-bis-t-butylperoxy-3, 3,5-trimethylcyclohexane (1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexane), 2-bis (4,4-di (tert-butylperoxy) cyclohexyl) propane (2,2-di (4,4-di (tert-butylperoxy) cyclohexyl) propane), and the like; peroxyesters (peroxiters) such as: t-butyl peroxypivalate (t-butyl peroxypivalate), 2,5-dimethyl-2,5-di (2-ethylhexanol peroxy) hexane (2,5-dimethyl-2,5-di (2-ethylhexyloxy) hexane), etc.; peroxyketal compounds, for example: 4, 4-di-t-butylperoxy-n-butyl valerate (4,4-di-t-butyl peroxide equivalent acid-n-butyl ester, abbreviated as TX-17); peroxycarbonates (peroxycarbonates) such as: 2-ethylhexyl tert-amyl peroxycarbonate (tert-amyl 2-ethylhexyl carbonate), 2-ethylhexyl tert-butyl peroxycarbonate (tert-butyl 2-ethylhexyl carbonate), and the like; or azo compounds having a nitro group and a cyclohexane group. The amount of the polymerization initiator added is in the range of 0.01 to 2.0 parts by weight, preferably 0.01 to 1.0 part by weight, based on 100 parts by weight of the total amount of the styrenic monomer and the acrylonitrile monomer.

In addition, in the preparation of the styrene-acrylonitrile copolymer (A), a thermal polymerization method may be employed in addition to the addition of the polymerization initiator to the reaction as described above.

Additionally, the reactors used to carry out the foregoing reactions may include (but are not limited to): a complete mixing continuous reactor (CSTR), a Plug Flow Reactor (PFR), or a tube reactor containing static mixing elements, etc., wherein a complete mixing continuous reactor is preferred. The number of the reactors to be used may be one, or two or more of them may be used in combination.

In one embodiment, the styrene-acrylonitrile copolymer (a) has a molecular weight of 60,000 to 400,000.

In addition, in the present embodiment, the method for producing the acrylate-based rubber graft copolymer (B) includes: graft polymerization of the acrylate-based rubber emulsion was carried out. In detail, the preparation method of the acrylate rubber emulsion comprises the following steps: an acrylate monomer is subjected to emulsion polymerization in the presence of an initiator. Specific examples of the acrylate-based monomer include (but are not limited to): methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, and the like, with n-butyl acrylate being preferred.

The initiator may be any of various conventional radical polymerization initiators other than Cumene Hydroperoxide (CHP), and may be added in one portion, continuously or incrementally, or the like. In detail, specific examples of the initiator include (but are not limited to): p-menthane peroxide (PMHP), tert-butyl peroxide (tert-butyl peroxide), lauroyl peroxide (lauroyl peroxide), octadecanoyl peroxide (oleyl peroxide), tert-butyl peracetate (tert-butyl peracetate), isopropyl peroxy dicarbonate (isopropylperoxy dicarbate), 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane (2,5-dimethyl-2,5-di (tert-butylperoxy) hexane), tert-butyl hydroperoxide (tert-butyl hydroperoxide), 2,5-dimethyl-2,5-di (tert-butylperoxy) -hexyl-3-tert-butyl hydroperoxide (2,5-dimethyl-2,5-di (tert-butyl hydroperoxide)) benzene, Cyclopentylated hydroperoxide, pinane hydroperoxide, 2, 5-dimethyl-hexyl-2, 5-dihydroperoxide or mixtures thereof. In one embodiment, the total amount of the initiator is preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the total acrylate monomers.

In addition, the preparation method of the acrylate rubber emulsion can further comprise adding a bridging agent during the polymerization reaction. The bridging agent includes (but is not limited to): ethylene diacrylate, butylene diacrylate, divinylbenzene, butylene glycol dimethacrylate, trimethylolpropane tri (meth) acrylate, Allyl Methacrylate (AMA), diallyl methacrylate, diallyl maleate, diallyl fumarate, diallyl phthalate, triallyl methacrylate, triallyl cyanurate, triallyl isocyanurate, the acrylate of tricyclodecenylalcohol, the diacrylate of polyalkylene glycol, etc., wherein the aforementioned crosslinking agents may be used alone or in combination of 2 or more. In one embodiment, the amount of the bridging agent is preferably 0.1 wt% to 10 wt%, based on 100 wt% of the total weight of the acrylate monomers and the bridging agent.

In addition, the average particle diameter of the acrylate-based rubber emulsion can be controlled by polymerization conditions, for example: the polymerization temperature; the amount and type of the initiator, emulsifier and activator; the method of adding the monomer, etc. The emulsifier is not particularly limited, but anionic emulsifiers selected from carboxylates such as sodium succinate, potassium fatty acid, sodium fatty acid, dipotassium alkenylsuccinate and soap rose, sulfonates such as alkyl sulfate and sodium alkylbenzenesulfonate, and sodium polyoxyethylene nonylphenyl ether sulfate are preferable in order to improve the stability of the emulsion during the emulsion polymerization and to increase the polymerization rate. Specific examples of the activating agent include (but are not limited to): ferrous sulfate, sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, tetrasodium pyrophosphate, etc.

The weight average particle diameter of the acrylate-based rubber emulsion may be a monomodal distribution or a bimodal distribution. In one embodiment, the weight average particle size of the acrylate-based rubber emulsion is in a unimodal distribution of 0.05 μm to 1 μm. In another embodiment, the weight average particle size of the acrylate-based rubber emulsion is in a monomodal distribution between 0.05 μm and 0.2 μm. In yet another embodiment, the weight average particle size of the acrylate-based rubber emulsion is in a monomodal distribution between 0.26 μm and 0.5 μm. In another embodiment, the weight average particle size of the acrylate rubber latex is in a bimodal distribution of 0.05 μm to 0.2 μm and 0.26 μm to 0.5 μm.

The graft polymerization of the acrylate-based rubber emulsion comprises: in the presence of an initiator, 100 parts by weight (dry weight) of the acrylate-based rubber emulsion and 50 to 100 parts by weight of a monomer mixture are subjected to graft polymerization, wherein the monomer mixture comprises 64 to 78 weight percent of styrene-based monomers and 22 to 36 weight percent of acrylonitrile-based monomers. The aforementioned monomer mixture may be added in a single addition, in portions, continuously or in portions of the monomers in the monomer mixture. In addition, as mentioned above, when the weight average particle size of the acrylate-based rubber emulsion is bimodal, the two acrylate-based rubber emulsions can be separately graft polymerized and then mixed, or the two acrylate-based rubber emulsions can be graft polymerized in a mixed state. Specifically, in the present embodiment, the composition of the acrylate-based rubber graft copolymer (B) includes 5 wt% to 25 wt% of an acrylonitrile-based monomer unit, 25 wt% to 45 wt% of a styrene-based monomer unit, and 40 wt% to 70 wt% of an acrylate-based monomer unit, preferably 5 wt% to 20 wt% of the acrylonitrile-based monomer unit, 30 wt% to 40 wt% of the styrene-based monomer unit, and 40 wt% to 60 wt% of the acrylate-based monomer unit.

Specific examples of the styrenic monomer include, but are not limited to, styrene, α -methylstyrene, p-tert-butylstyrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, 2, 4-dimethylstyrene, ethylstyrene, α -methyl-p-methylstyrene, bromostyrene, etc., of which styrene or α -methylstyrene is preferable, and specific examples of the acrylonitrile monomer include, but are not limited to, acrylonitrile, α -methacrylonitrile, etc., of which acrylonitrile is preferable.

The initiator may be any of various conventional radical polymerization initiators other than cumene hydroperoxide, and may be added in a single addition, continuously or incrementally, or the like. In detail, specific examples of the initiator include (but are not limited to): p-menthane peroxide, tert-butyl peroxide, lauroyl peroxide, octadecanoyl peroxide, tert-butyl peroxyacetate, isopropyl peroxydicarbonate, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyl-3-tert-butyl hydroperoxide, 2,5-di (tert-butylperoxy) 2,5-di (tert-butyl-peroxy) benzene, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyl-3-tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di (tert-butyl-peroxy) hexyl-3-tert-butyl hydroperoxide, Cyclopentylated hydrogen peroxide (pinene hydroperoxide), 2, 5-dimethyl-hexyl-2, 5-dihydroperoxide (2,5-dimethyl-hexane-2,5-dihydroperoxide) or mixtures thereof. In one embodiment, the total amount of the initiator used is preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the total monomer mixture.

It is worth mentioning that if p-menthane peroxide is used as an initiator in the emulsion polymerization reaction, p-menthane peroxide can be used as an initiator or not in the graft polymerization reaction; on the other hand, if p-menthane peroxide is not used as an initiator in the emulsion polymerization, p-menthane peroxide must be used as an initiator in the graft polymerization. That is, in the present embodiment, in the process of preparing the acrylate-based rubber graft copolymer (B), at least one of the emulsion polymerization reaction and the graft polymerization reaction uses p-menthane peroxide as an initiator. Also, it is preferable that the graft polymerization reaction uses p-menthane peroxide as an initiator in the preparation of the acrylate-based rubber graft copolymer (B).

Specifically, in the present embodiment, the total amount of p-menthane peroxide used as the initiator is less than 1 part by weight and more than 0.05 part by weight based on 100 parts by weight of the acrylate monomer in the emulsion polymerization reaction. In the emulsion polymerization reaction, if the using amount of the p-menthane hydroperoxide is more than or equal to 1 part by weight, the gloss and the heat resistance of the rubber modified resin composition are poor; if the amount of p-menthane peroxide used is 0.05 parts by weight or less, the impact resistance of the rubber-modified resin composition will be significantly insufficient. In the present embodiment, the total amount of p-menthane peroxide used as the initiator in the graft polymerization reaction is less than 1.3 parts by weight and more than 0.35 parts by weight based on 100 parts by weight of the acrylic ester-based rubber emulsion in terms of dry weight. If the amount of p-menthane peroxide used in the graft polymerization is 1.3 parts by weight or more, the flowability of the rubber-modified resin composition will be too high; if the amount of p-menthane peroxide used is less than or equal to 0.35 parts by weight, the flowability of the rubber-modified resin composition will be too low.

Furthermore, the p-menthane contained in the rubber modified resin composition is a product generated after the hydrogen peroxide initiator is reacted, namely, the p-menthane is a byproduct in the process of preparing the acrylate rubber graft copolymer (B). As described above, the initiator is not a hydrogen peroxide initiator that generates acetophenone after the reaction in both the emulsion polymerization reaction and the graft polymerization reaction, and therefore the rubber-modified resin composition does not contain acetophenone. In addition, in the present embodiment, since the detection limit of the gas chromatograph used for acetophenone is 1ppm, the rubber modified resin composition does not contain acetophenone, which means that the content of acetophenone is less than 1 ppm.

In addition, the graft ratio of the acrylate-based rubber graft copolymer (B) can be controlled by polymerization reaction conditions such as: the polymerization temperature; the amount and type of initiator, emulsifier, activator, chain transfer agent; the amount of the monomer used and the method of addition are controlled. In one embodiment, the reaction temperature for the graft polymerization is below 90 ℃, preferably between 25 ℃ and 40 ℃.

The emulsifier is not particularly limited, but anionic emulsifiers selected from carboxylates such as sodium succinate, potassium fatty acid, sodium fatty acid, dipotassium alkenylsuccinate and soap rose, sulfonates such as alkyl sulfate and sodium alkylbenzenesulfonate, and sodium polyoxyethylene nonylphenyl ether sulfate are preferable in order to improve the stability of the emulsion during the emulsion polymerization and to increase the polymerization rate. Specific examples of the activating agent include (but are not limited to): ferrous sulfate, sodium formaldehyde sulfoxylate, sodium ethylenediamine tetraacetate, tetrasodium pyrophosphate, etc. Specific examples of the chain transfer agent include (but are not limited to): n-butyl mercaptan (n-butylmercaptan), n-octyl mercaptan (n-octyl mercaptan), n-dodecyl mercaptan (n-dedecylmercaptan), tert-dodecyl mercaptan (tert-dedecylmercaptan). In one embodiment, the chain transfer agent is preferably used in an amount of 0.01 to 5 parts by weight, based on 100 parts by weight of the total monomer mixture.

The weight average particle diameter of the acrylate-based rubber graft copolymer (B) may be a monomodal distribution or a bimodal distribution. In one embodiment, the weight average particle diameter of the acrylate-based rubber graft copolymer (B) is in a monomodal distribution of 0.05 μm to 0.22. mu.m. In another embodiment, the weight average particle size of the acrylate-based rubber emulsion is in a monomodal distribution between 0.26 μm and 0.55 μm. In another embodiment, the weight average particle size of the acrylate-based rubber latex is bimodal between 0.05 μm and 0.22 μm and between 0.26 μm and 0.55 μm.

The rubber-modified resin composition of the present embodiment may further contain an additive. The additive is selected from the group consisting of antioxidants, slip agents, plasticizers, processing aids, UV stabilizers, UV absorbers, fillers, reinforcing agents, colorants, antistatic agents, flame retardants, flame retardant aids, heat stabilizers, coupling agents, and combinations thereof.

The antioxidant may be used alone or in combination, and the antioxidant includes, but is not limited to, phenol-based antioxidants, thioether-based antioxidants, or phosphorus-based antioxidants, and specific examples of the phenol-based antioxidants include, but are not limited to, octadecyl 3,5-bis (1,1-dimethylethyl) -4-hydroxyphenylpropionate (3,5-bis (1, 1-dimethyleth-yl) -4-hydroxybenzenepropanoic acid octadecester, type i.e., antioxidant IX-1076), triethylene glycol bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate ], tetrakis [ methylene-3- (3, 5-bis-tert-butyl-4-hydroxyphenyl) propionate ] methane, 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-6-methylphenyl) -4-methylphenylacrylate, 2'-methylene-bis (4-methyl-6-hydroxyphenyl) propionate) (2, 2-tert-butyl-2-hydroxy-6-methylphenyl) -4-methylphenylacrylate, 2' -methylpoly-bis (3-tert-butyl-4-hydroxyphenyl) propionate), or the antioxidant may include, but is not limited to, 2-bis (3, 5-tert-butyl-4-dihydrobutylphenol-4-phosphite), and specific examples of the antioxidant include, 5-bis (3, 5-butyl-diphenyl-4-bis-4-butyl-diphenyl-3, 5-bis-4-2-butyl-thiodipropyl) phosphite, 2-tert-butyl-2-butyl-2-tert-hydroxy-6-butyl-2-butyl-4-diphenyl-2-dihydrophosphite, 5-diphenyl-2-4-diphenyl-2-butyl-2-butyl-diphenyl-2-tert-2-butyl-2-tert-2-tert-butyl-2-tert-butyl-tert-2-tert-butyl-thiodiphenyl-butyl-4-2-butyl-2-diphenyl-butyl-2-.

The slip agents may be used alone or in admixture, and specific examples of slip agents include (but are not limited to): metal soaps such as calcium stearate, magnesium stearate, and lithium stearate, ethylene bis-stearamide (EBA), isopentyl stearate (PETS), methylene distearyl amide, palmitamide, butyl stearate, palmityl stearate, pentaerythritol tetra-fatty acid ester, polyallyl alcohol tristearate, n-behenic acid, and compounds such as stearic acid, polyethylene wax, octacosane wax, carnauba wax (carnauba wax), and petroleum wax.

In one embodiment, the additive is contained in an amount ranging from 0.01 parts by weight to 20 parts by weight, based on 100 parts by weight of the total rubber modified resin composition.

Another embodiment of the present invention provides a method for preparing a rubber-modified resin composition, comprising: after providing the styrene-acrylonitrile copolymer (a) and the acrylate-based rubber graft copolymer (B) in any of the above embodiments, the styrene-acrylonitrile copolymer (a) and the acrylate-based rubber graft copolymer (B) are kneaded to form the rubber-modified resin composition. The description of the rubber-modified resin composition, the styrene-acrylonitrile copolymer (A) and the acrylate rubber graft copolymer (B) is given in detail in the above embodiments, and thus will not be repeated herein.

In the present embodiment, the method for kneading the styrene-acrylonitrile copolymer (a) and the acrylate-based rubber graft copolymer (B) is not particularly limited, and any kneading method known to those skilled in the art can be used. In one embodiment, the method for kneading the styrene-acrylonitrile copolymer (a) and the acrylate-based rubber graft copolymer (B) comprises: the resulting mixture is dry-blended in a general Henschel mixer, and then melt-blended in a mixer such as an extruder, kneader or Banbury mixer.

The rubber-modified resin composition may further contain an additive which is added during the polymerization reaction for preparing the styrene-acrylonitrile copolymer (A) and the acrylate-based rubber graft copolymer (B), after the polymerization reaction, before coagulation, or during kneading of the styrene-acrylonitrile copolymer (A) and the acrylate-based rubber graft copolymer (B).

It should be noted that, as described above, in the process of preparing the acrylate-based rubber graft copolymer (B), at least one of the emulsion polymerization reaction and the graft polymerization reaction uses p-menthane peroxide as an initiator, so that the final product contains p-menthane as a byproduct, and the styrene-acrylonitrile-based copolymer (a) and the acrylate-based rubber graft copolymer (B) are kneaded to form the rubber modified resin composition containing p-menthane in a specific content. On the other hand, in the process of preparing the acrylic rubber graft copolymer (B), since the initiator is not isopropylbenzene hydroperoxide which generates acetophenone after the reaction, both in the emulsion polymerization reaction and in the graft polymerization reaction, the styrene-acrylonitrile copolymer (a) and the acrylic rubber graft copolymer (B) are kneaded to form a rubber-modified resin composition which does not contain acetophenone at all.

In this way, the rubber-modified resin composition obtained by the method for preparing a rubber-modified resin composition according to the embodiment solves the problem of acetophenone residues, and further improves the odor by containing p-menthane. On the other hand, the rubber-modified resin composition obtained by the method for producing a rubber-modified resin composition according to the present embodiment includes the styrene-acrylonitrile copolymer (a), the acrylate-based rubber graft copolymer (B), and p-menthane in a specific content range, and has good impact resistance, heat resistance, and surface gloss.

The features of the present invention will be described more specifically below with reference to examples 1 to 8 and comparative examples 1 to 4. Although the following examples 1 to 8 are described, the materials used, the amounts and ratios thereof, the details of the treatment, the flow of the treatment, and the like may be appropriately changed without departing from the scope of the present invention. Therefore, the present invention should not be construed restrictively by the examples described below.

Synthesis example 1

Preparation of styrene-acrylonitrile copolymer (A)

76 parts by weight of styrene, 24 parts by weight of acrylonitrile, 8 parts by weight of ethylbenzene, 0.01 part by weight of 1, 1-di-tert-butylperoxy-3, 3,5-trimethylcyclohexane and 0.15 part by weight of tert-dodecylmercaptan were mixed and continuously fed at a rate of 35kg/hr into two serially connected, completely mixed, continuous reactors, each having a volume of 40 liters, the internal temperatures of 2 reactors were maintained at 110 ℃ and 115 ℃ respectively, and the pressure of each reactor was maintained at 4kg/cm²The overall conversion is about 50%.

After the polymerization was completed, the resulting copolymer solution was heated with a preheater. Subsequently, the unreacted monomer and other volatile matters were devolatilized in a vacuum degassing vessel, and then extruded and pelletized, whereby the styrene-acrylonitrile copolymer (A) of Synthesis example 1 was obtained.

Synthesis example 2

Preparation of acrylate-based rubber graft copolymer (B)

First, 99.0 parts by weight of n-butyl acrylate, 1.0 part by weight of allyl methacrylate, 0.1 part by weight of p-menthane hydroperoxide, 3.0 parts by weight of a ferrous sulfate solution (concentration: 0.2% by weight), 3.0 parts by weight of a sodium formaldehyde sulfoxylate solution (concentration: 10% by weight) and 4000.0 parts by weight of distilled water were subjected to emulsion polymerization at a reaction temperature of 60 ℃ for 7 hours to obtain an acrylate-based rubber emulsion (solid content: about 38%) having a weight average particle size of 0.1 μm.

Next, 99.0 parts by weight of n-butyl acrylate, 1.0 part by weight of allyl methacrylate, 0.1 part by weight of p-menthane hydroperoxide, 3.0 parts by weight of a ferrous sulfate solution (concentration: 0.2 wt%), 3.0 parts by weight of a sodium formaldehyde sulfoxylate solution (concentration: 10 wt%) and 4000.0 parts by weight of distilled water were subjected to emulsion polymerization at a reaction temperature of 65 ℃ for 7 hours to obtain an acrylate-based rubber emulsion (solid content: about 38%) having a weight average particle size of 0.4 μm.

Then, 30.0 parts by weight of the acrylic ester-based rubber emulsion (dry weight) having the weight average particle size of 0.4 μm, 70.0 parts by weight of the acrylic ester-based rubber emulsion (dry weight) having the weight average particle size of 0.1 μm, 70.0 parts by weight of styrene, 30.0 parts by weight of acrylonitrile, 0.86 parts by weight of p-menthane hydroperoxide, 3.0 parts by weight of ferrous sulfate solution (concentration: 0.2 wt%), 3.0 parts by weight of sodium formaldehyde sulfoxylate solution (concentration: 10 wt%), and 3000.0 parts by weight of distilled water were mixed and subjected to graft polymerization. After the graft polymerization reaction is completed, the acrylate-based rubber graft emulsion can be obtained.

Finally, the obtained acrylate-based rubber graft emulsion is treated with calcium chloride (CaCl)₂) After coagulation and dehydration, the resulting product was dried to a water content of 2% or less, thereby obtaining an acrylate-based rubber graft copolymer of Synthesis example 2 having a bimodal distribution of 0.12 μm and 0.45 μm in weight average particle diameter.

Synthesis examples 3 to 12

Preparation of acrylate-based rubber graft copolymer (B)

The acrylate-based rubber graft copolymers of Synthesis examples 3 to 12 were prepared according to a similar preparation procedure to Synthesis example 1, and according to the kind and amount of the initiator shown in Table 1.

The abbreviations in table 1 are described below:

compound represented by abbreviation

BHP tert-butyl hydroperoxide

CHP isopropylbenzene hydroperoxide

PMHP p-menthane hydroperoxide

Example 1

Preparation of rubber-modified resin composition

In a dry state, 54.1% by weight of the styrene-acrylonitrile copolymer (A) of Synthesis example 1, 45.9% by weight of the acrylate-based rubber graft copolymer (B) of Synthesis example 2 and 2.0% by weight of a lubricant were kneaded at a kneading temperature of 220 ℃ by means of a biaxial extruder (model: ZPT-25, manufactured by Zezer industries, Ltd.). Then, the mixture was extruded by a twin screw extruder to obtain the rubber modified resin composition of example 1.

Examples 2 to 8 and comparative examples 1 to 4

Preparation of rubber-modified resin composition

The rubber-modified resin compositions of examples 2 to 8 and comparative examples 1 to 4 were prepared according to the similar preparation procedures as in example 1, and the kinds and amounts of the raw materials shown in Table 2. The weight% in table 2 is based on the total weight of the styrene-acrylonitrile copolymer (a) and the acrylate rubber graft copolymer (B).

Then, the rubber-modified resin compositions of examples 1 to 8 and comparative examples 1 to 4 were subjected to: determination of acetophenone content, determination of p-menthane content, determination of Melt Index (MI), determination of softening point temperature (softening point), determination of Izod and determination of surface gloss (gloss). The descriptions of the foregoing are as follows, and the measurement results are shown in table 3. In addition, nd in Table 3 indicates that it was not determined because the detection limit of the gas chromatograph for acetophenone was 1ppm, and thus nd indicates that it was not determined that the acetophenone content was less than 1 ppm.

Determination of acetophenone content

The instrument comprises the following steps: gas chromatograph (gas chromatograph, GC) (model: Agilent 6890GC/FID)

The model of the pipe column: HP-530M 0.32mm 0.25 um.

Pretreatment: 1 g of the sample (i.e., the rubber-modified resin compositions of examples 1 to 8 and comparative examples 1 to 4) was dissolved in 5 ml of methylene chloride and extracted with 10 ml of methanol. Then, the clear solution was injected into a GC for quantification.

Temperature rising conditions are as follows: the temperature was raised from 60 ℃ per minute to 10 ℃ to 300 ℃ and the residence time was 11 minutes.

Determination of the content of p-menthane

The content of the acetophenone is measured.

Measurement of melting coefficient

The measurement was carried out according to ASTM D-1238 under conditions of 220 ℃ and a load of 10Kg, in units of: g/10 min. In the field of general rubber-modified resin compositions, the MI is usually at least greater than 5g/10min and less than 12g/10min, and a higher value indicates better fluidity, i.e., better moldability of the rubber-modified resin composition.

Measurement of softening point temperature

The softening point temperature was measured according to ASTM D-1525, in units of: DEG C. Generally, a higher softening point temperature indicates better heat resistance.

Measurement of moxa-like impact strength

The rubber-modified resin compositions of examples 1-8 and comparative examples 1-4 were each injection molded by an injection molding machine (model: SM-150, manufactured by Samsung mechanical Co., Ltd.) into 1/8-inch test pieces with a notch, and the test pieces were measured according to ASTM D-256. The unit is: kg cm/cm. In the field of general rubber-modified resin compositions, the Izod standard is at least more than 10Kg cm/cm, and a higher value indicates better impact resistance.

Measurement of surface gloss

The rubber-modified resin compositions of examples 1 to 8 and comparative examples 1 to 4 were each injection-molded into a disk test piece having a diameter of 5.5cm by means of an injection molding machine (model: SM-150, manufactured by Samsung machinery Co., Ltd.), and measured in accordance with ASTM D-523 in units of: % of the total weight of the composition.

Measurement of odor

Sealing the prepared resin in a glass sample bottle for one day, and opening the bottle to allow the bottle to be directly smelled by a human body.

◎ with no odor and fragrance

No odor ○

Slightly odorous: delta

Strong odor: x

As can be seen from the above Table 3, the rubber modified resin compositions of examples 1-8 all contained no acetophenone and p-menthane in the range of 19ppm to 68 ppm; on the other hand, the rubber-modified resin compositions of comparative examples 1 to 4 all contained acetophenone, and were liable to cause unpleasant odor. Therefore, the rubber-modified resin compositions of examples 1 to 8 did not have the problem of generating odor due to acetophenone residues, and further improved odor by containing p-menthane, thereby avoiding discomfort to human body during application and having good applicability, as compared with the rubber-modified resin compositions of comparative examples 1 to 4.

In addition, as is clear from the above Table 3, the rubber-modified resin compositions of examples 1 to 8 were excellent in all of softening point temperature, Izod impact strength and surface gloss. This result confirmed that the rubber-modified resin compositions of examples 1 to 8 not only did not contain acetophenone residues, but also maintained the physical properties required for industrial processing.

In addition, as can be seen from the above Table 3, the rubber-modified resin compositions of examples 1 to 6 exhibited excellent properties in terms of melt modulus. This result shows that in the process of preparing the acrylate-based rubber graft copolymer (B), good fluidity of the rubber-modified resin composition can be achieved by performing graft polymerization using p-menthane hydroperoxide in an amount of less than 1.3 parts by weight and more than 0.35 parts by weight as an initiator.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rubber-modified resin composition comprising:

a continuous phase of a styrene-acrylonitrile copolymer (A);

a dispersed phase formed of an acrylate-based rubber graft copolymer (B); and

the rubber modified resin composition contains no acetophenone, wherein the acrylate rubber graft copolymer (B) is obtained by graft polymerization of 100 parts by weight of acrylate rubber emulsion and 50 to 100 parts by weight of monomer mixture, and the monomer mixture contains 64 to 78 weight percent of styrene monomer and 22 to 36 weight percent of acrylonitrile monomer.

2. The rubber-modified resin composition of claim 1, wherein the amount of p-menthane is more than 8ppm and less than 150 ppm.

3. The rubber-modified resin composition of claim 1, wherein the styrene-acrylonitrile copolymer (A) is present in an amount of 40 to 90 wt% and the acrylate-based rubber graft copolymer (B) is present in an amount of 10 to 60 wt%, based on 100 wt% of the total weight of the styrene-acrylonitrile copolymer (A) and the acrylate-based rubber graft copolymer (B).

4. The rubber-modified resin composition according to claim 1, wherein the rubber-modified resin composition comprises, based on 100 wt% of the total weight of the styrene-acrylonitrile copolymer (A) and the acrylate-based rubber graft copolymer (B): 15 to 25 wt% of acrylonitrile monomer units, 55 to 65 wt% of styrene monomer units and 15 to 25 wt% of acrylate monomer units.

5. The rubber-modified resin composition of claim 1, wherein the weight average particle diameter of the acrylate-based rubber graft copolymer (B) is unimodal distribution of 0.05 μm to 0.22 μm, unimodal distribution of 0.26 μm to 0.55 μm, or bimodal distribution of 0.05 μm to 0.22 μm and 0.26 μm to 0.55 μm.

6. A method for preparing a rubber-modified resin composition, comprising:

provided are a styrene-acrylonitrile copolymer (A) and an acrylate rubber graft copolymer (B), wherein the preparation method of the acrylate rubber graft copolymer (B) comprises the following steps: carrying out emulsion polymerization reaction on an acrylate monomer in the presence of a first initiator to form acrylate rubber emulsion; and subjecting the acrylate-based rubber emulsion to a graft polymerization reaction, wherein subjecting the acrylate-based rubber emulsion to the graft polymerization reaction comprises: subjecting 100 parts by weight of the acrylate-based rubber emulsion in dry weight to graft polymerization with 50 to 100 parts by weight of a monomer mixture in the presence of a second initiator, wherein the monomer mixture comprises 64 to 78% by weight of styrene-based monomers and 22 to 36% by weight of acrylonitrile-based monomers, the first initiator and the second initiator are not isopropylbenzene hydroperoxide, and at least one of the first initiator and the second initiator is p-menthane peroxide, wherein in the emulsion polymerization, when the first initiator is p-menthane peroxide, the total usage amount of the first initiator is less than 1 part by weight and more than 0.05 part by weight based on 100 parts by weight of acrylate-based monomers, and in the graft polymerization, when the second initiator is p-menthane peroxide, the total usage amount of the second initiator is less than 1.3 parts by weight and more than 0.35 part by weight based on 100 parts by weight of the dry weight of the acrylate-based rubber emulsion; and

the styrene-acrylonitrile copolymer (A) and the acrylate rubber graft copolymer (B) are kneaded, wherein the rubber modified resin composition contains p-menthane, the content of the p-menthane is more than 5ppm and less than 180ppm, and the rubber modified resin composition does not contain acetophenone.

7. The method of claim 6, wherein the second initiator is p-menthane hydroperoxide.

8. The method of claim 7, wherein the first initiator is p-menthane hydroperoxide.