CN107245214B - High-efficiency anti-mildew AES resin composition and preparation method thereof - Google Patents

Abstract

The invention discloses a high-efficiency anti-mildew AES resin composition and a preparation method thereof, wherein the composition comprises the following components: 10-50 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 50-90 parts of acrylonitrile-styrene copolymer, 0.1-10.0 parts of antibacterial agent, 0.01-1.0 part of initiator, 0.01-1.0 part of crosslinking inhibitor and 0.1-5.0 parts of processing aid; the thermoplastic AES resin composition prepared by the invention has the advantages of excellent anti-mildew effect, outstanding mechanical property, high color retention rate and the like, and well solves the problems of bacterial intolerance, mildew deterioration and color change after the AES resin composition is used outdoors for a long time; the resin composition has high mechanical property, can meet the use requirements of most parts, and is particularly suitable for AES products (building materials, sports equipment, communication equipment shells, automobile parts and other outdoor products) with antifungal requirements.

Description

High-efficiency anti-mildew AES resin composition and preparation method thereof

Technical Field

The invention relates to the technical field of high polymer materials, and particularly relates to a high-efficiency antifungal AES resin composition and a preparation method thereof.

Background

Acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer (AES) is a weather resistant engineering plastic, which has a structure similar to that of acrylonitrile-butadiene-styrene graft copolymer (ABS) and retains the excellent mechanical and physical properties of ABS as an engineering plastic. AES resin is mostly applied to outdoor occasions with higher weather resistance requirements, the service life of products is generally longer, and under the action of long-term illumination, temperature and humidity, chemical reagents and microorganisms, mould is easily bred on the surface of the resin, so that the mould is corroded into a molecular chain, a chemical structure is damaged, the appearance of the products is adversely affected, and in severe cases, the products can show the bad effects of surface pulverization, product fracture and the like, so that the use safety and the service life are seriously affected; therefore, it is important to perform an antifungal treatment on the AES resin.

At present, the effective method for improving the mould resistance of resin is to add antibacterial and mildewproof substances which can be mainly divided into three categories of inorganic, synthetic organic and natural organic, wherein the inorganic antibacterial agent is an earlier-researched antibacterial agent which is prepared by exchanging antibacterial metal ions such as silver, copper, zinc and the like through an inorganic carrier; the material has the advantages of antibacterial property, good high-temperature resistance, difficult decomposition of metal ions and the like. However, inorganic antibacterial agents have disadvantages such as easy discoloration, high price, and easy leaching, and have high requirements for photocatalysis, which limits their industrial application.

The organic antibacterial agent can be divided into a natural antibacterial agent and an organic synthetic antibacterial agent from the aspect of antibacterial groups, and the natural antibacterial agent has the defects of insufficient heat resistance, poor durability of antibacterial effect, difficult processing and the like; the synthetic organic antibacterial agent has the characteristics of broad spectrum, high efficiency, durability, strong processability and the like, but has the defects of poor heat resistance, reduced mechanical performance and the like.

Research reports also exist that the anti-mould effect of the resin is improved by a method of compounding inorganic and organic antibacterial agents, but the problems of poor mechanical property, easy color change and the like exist; patent CN 103740024A discloses an antibacterial AES composite material and a preparation method thereof, wherein the antibacterial property of the material is realized by using a compounding mode of montmorillonite and tetradecyl tributyl phosphonium salt, but the patent only researches the performance condition after adding a composite antibacterial agent, does not analyze the performance difference of the composite material with and without the antibacterial agent, and actually, after inorganic substances are added, the toughness and the appearance of the material are influenced to a certain extent; patent CN 103059494B discloses an antibacterial ASA plastic, which is compounded by adding cedar oil, chitosan, nano titanium dioxide, nano silver oxide, poly hexamethylene guanidine phosphonium salt and N- (trichloromethylthio) phthalimide to improve the sterilization and mildew-proof effects, but the method has higher cost and is not beneficial to industrial production.

However, no AES resin can achieve effective anti-mildew performance under the conditions that the mechanical performance is not reduced and the AES resin is not discolored after being blended.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a high-efficiency anti-mildew AES resin composition and a preparation method thereof; the AES resin composition has excellent anti-mildew performance; meanwhile, the color retention rate of the material after long-term anti-mildew is greatly improved.

The purpose of the invention is realized by the following technical scheme:

the invention relates to a high-efficiency antifungal AES resin composition, which comprises the following components in parts by weight:

preferably, the acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer has a core-shell structure formed by grafting acrylonitrile and styrene by taking ethylene propylene diene monomer as a soft core.

Preferably, the weight-average molecular weight of the acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer is 50,000-200,000, the relative density is 1.0-1.04, the average diameter range is 0.1-4.0 μm, the weight percentage content of the ethylene propylene diene monomer is 35-85%,

more preferably, the average diameter of the acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer is 200-500 nm, and the weight percentage content of the ethylene propylene diene monomer is 60-80%. The average diameter of the acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer is too small, the toughening effect is not high, the particle size is too large, the surface of the material is prone to generating flowers, and the appearance is directly influenced; the ethylene propylene diene monomer has too low weight percentage content, the toughness of the material is insufficient, the weight percentage content is too high, and the mechanical strength and the rigidity of the material are reduced.

Preferably, the acrylonitrile-styrene copolymer has a weight average molecular weight of 100,000-500,000, and the acrylonitrile content is 15-40 wt%.

More preferably, the acrylonitrile-styrene copolymer has a weight average molecular weight of 200,000 to 400,000, and the acrylonitrile content is 25 to 35% by weight. The acrylonitrile-styrene copolymer has too low weight average molecular weight, poor toughness and thermal stability of the material, too high weight average molecular weight, influenced flowability and reduced processability; when the acrylonitrile content is within this range, the AES resin has relatively high overall impact properties and superior mechanical properties.

Preferably, the antimicrobial agent is selected from synthetic organic antimicrobial agents.

More preferably, the synthetic organic antibacterial agent comprises one or more of quaternary ammonium salts, triphenylphosphine, tributylphosphine, alkyltributylphosphine, polyhexamethylguanidine hydrochloride, polyhexamethylguanidine stearate, 3-methyl-4-isopropylphenol, 2-pyridinol-1-sodium oxide, 2- (4-thiazolyl) benzothiazole, 2-n-octyl-4-isothiazolin-3-one, 8-hydroxyquinoline ester and isopropanol.

Preferably, the initiator is one of azobisisobutyronitrile, azobisisoheptonitrile, di-tert-butyl peroxide, dicumyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, benzoyl peroxide, lauroyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, cyclohexanone peroxide, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.

Preferably, the crosslinking inhibitor is one of triphenyl phosphite, N ' -dimethylformamide, N ' -dimethylacetamide, N ' -diethylcinnamamide or dimethyl sulfoxide.

Preferably, the processing aid comprises one or more of a lubricant, an antioxidant and a weather-resistant agent.

Preferably, the lubricant is pentaerythritol stearate or ethylene bis stearamide.

Preferably, the antioxidant is a hindered phenol antioxidant or a phosphite antioxidant.

Preferably, the weather resisting agent is a benzotriazole ultraviolet absorbent or a hindered amine free radical scavenger.

The invention also relates to a preparation method of the high-efficiency antifungal AES resin composition, which comprises the following steps:

s1, weighing the raw materials according to the proportion;

s2, premixing the raw materials prepared in the step S1 in a high-speed mixer;

and S3, feeding the premix obtained in the step S2 into a double-screw extruder through a metering device, melting and compounding materials under the conveying, shearing and mixing of screws, and then carrying out extrusion, strip drawing, cooling and grain cutting to obtain the AES resin composition.

Preferably, the length-diameter ratio of a screw of the double-screw extruder is 36-44, and the double-screw extruder is provided with a temperature control device and a vacuumizing device; the extrusion temperature of the double-screw extruder is 180-250 ℃, and the rotating speed of the screw is 200-500 r/min.

Compared with the prior art, the invention has the following beneficial effects:

1. the composition is prepared by adopting a synthetic organic antibacterial agent, using a certain proportion of initiator and a certain proportion of crosslinking inhibitor to perform reactive extrusion with AES resin, grafting an antibacterial group onto an AES molecular chain segment, and controlling excessive crosslinking in the extrusion reaction through the crosslinking inhibitor. The resin composition can achieve a long-term and efficient anti-mold effect.

2. The composition has obviously improved mechanical properties, particularly heat resistance and impact resistance, and greatly solves the problem of the prior art that the physical property of the AES resin is reduced after the anti-mildew property is improved.

3. After long-time photoaging, the color change of the resin is equivalent to that of the common AES resin, is obviously superior to inorganic and natural organic antibacterial agents, and effectively solves the problem of color change after the resin and the antibacterial agent are mixed in the prior art.

Detailed Description

The present invention will be described in detail with reference to examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be apparent to those skilled in the art that several modifications and improvements can be made without departing from the inventive concept. All falling within the scope of the present invention.

The raw materials, parameters and grades used in the examples were as follows:

the acrylonitrile-ethylene propylene diene monomer rubber-styrene graft copolymer is an ethylene propylene diene monomer rubber graft styrene-acrylonitrile copolymer, the weight average molecular weight of the acrylonitrile-ethylene propylene diene monomer rubber graft styrene-acrylonitrile copolymer is 50,000-200,000, the relative density of the acrylonitrile-ethylene propylene diene monomer rubber graft copolymer is 1.0-1.04, the average diameter range of the acrylonitrile-ethylene propylene diene monomer rubber graft copolymer is 200-500 nm, and the weight percentage content of the ethylene propylene diene monomer rubber is 60-80 wt%. The weight average molecular weight of the acrylonitrile-styrene copolymer is 100,000-500,000, and the weight percentage content of acrylonitrile is 15-40 wt%. The synthetic organic antibacterial agent is quaternary ammonium salt (benzyl dimethyl dodecyl ammonium chloride, A-1), quaternary phosphonium salt (p-vinylbenzyl tributyl phosphonium chloride, A-2) and phenol (3-methyl-4-isopropyl phenol, A-3). The natural organic antibacterial agent is (chitosan, B-1). The inorganic antibacterial agent is (Ag + metal ion antibacterial agent, C-1). The processing aid is lubricant EBS and antioxidant Ciba IG-1076.

Example 1

40 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 60 parts of acrylonitrile-styrene copolymer, 3 parts of quaternary ammonium salt antibacterial agent (benzyl dimethyl dodecyl ammonium chloride, A-1), 0.1 part of dicumyl peroxide, 1 part of triphenyl phosphite and 0.6 part of processing aid. The raw materials are weighed according to the parts by weight, and the high-efficiency antifungal AES resin composition is prepared by the following method:

(1) fully mixing the prepared raw materials in a high-speed mixer for 30 min;

(2) and (2) feeding the premix prepared in the step (1) into a double-screw extruder through a metering device, melting and compounding materials under the conveying, shearing and mixing of screws, and then carrying out extrusion, bracing, cooling and grain cutting to obtain the high-efficiency antifungal AES resin composition. Wherein the length-diameter ratio of a screw of the double-screw extruder is 36-44, and the vacuum degree is controlled to be 0.09 Ma; the extrusion temperature of the double-screw extruder is 180-250 ℃, and the rotating speed of the screw is 200-500 r/min.

Examples 2 to 7

In order to embody the inventive property of the present invention by comparison, the compounding ratios of examples 2 to 7 were compared with the effects of different synthetic organic antibacterial agents, different addition amounts of the synthetic organic antibacterial agents, and different addition amounts of the initiator on the material properties based on example 1, the specific preparation methods were the same as example 1, and the raw material compounding ratios are shown in table 1. In addition, the processing aid in the embodiments 2 to 7 can be any value of 0.1 to 5.0, and the material component can be one or more of a lubricant, an antioxidant and a weather-resistant agent, and in order to enhance the comparability with the embodiment 1, the selected weight part is 0.6.

It is to be specifically noted that the amounts of the respective components used in the present invention are not limited to the above examples. Wherein, the acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer can be selected from 10 to 50 parts, the styrene-acrylonitrile copolymer can be selected from 50 to 90 parts, the antibacterial agent can be selected from 0.1 to 10.0 parts, the initiator can be selected from 0.01 to 1.0 part, and the crosslinking inhibitor can be selected from 0.01 to 1.0 part.

Comparative example 1

40 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 60 parts of acrylonitrile-styrene copolymer and 0.6 part of processing aid. The specific preparation method is the same as example 1, and the raw material formulation is shown in table 1.

Comparative example 2

40 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 60 parts of acrylonitrile-styrene copolymer, 3 parts of quaternary phosphonium salt antibacterial agent (p-vinylbenzyltributylphosphonium chloride, A-2) and 0.6 part of processing aid. The specific preparation method is the same as example 1, and the raw material formulation is shown in table 1.

Comparative example 3

40 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 60 parts of acrylonitrile-styrene copolymer, 3 parts of natural organic antibacterial agent (chitosan, B-1)), 0.1 part of dicumyl peroxide, 1 part of triphenyl phosphite and 0.6 part of processing aid. The specific preparation method is the same as example 1, and the raw material formulation is shown in table 1.

Comparative example 4

40 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 60 parts of acrylonitrile-styrene copolymer, 3 parts of inorganic antibacterial agent (Ag + series metal ion antibacterial agent, C-1), 0.1 part of dicumyl peroxide, 1 part of triphenyl phosphite and 0.6 part of processing aid. The specific preparation method is the same as example 1, and the raw material formulation is shown in table 1.

Comparative example 5

40 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 60 parts of acrylonitrile-styrene copolymer, 3 parts of quaternary phosphonium salt antibacterial agent (p-vinylbenzyltributylphosphonium chloride, A-2), 0.1 part of sodium thiosulfate, 1 part of triphenyl phosphite and 0.6 part of processing aid. The specific preparation method is the same as example 1, and the raw material formulation is shown in table 1.

Comparative example 6

40 parts of acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer, 60 parts of acrylonitrile-styrene copolymer, 3 parts of quaternary phosphonium salt antibacterial agent (p-vinylbenzyltributylphosphonium chloride, A-2), 0.1 part of dicumyl peroxide, 1 part of 1, 1-diphenyl-2-trinitrophenylhydrazine and 0.6 part of processing aid. The specific preparation method is the same as example 1, and the raw material formulation is shown in table 1.

TABLE 1 raw material formulations of examples 1-7 and comparative examples 1-4

Note: in the table, "/" indicates the absence of this component.

Performance testing

Test specimens were prepared from the AES resin compositions prepared in examples 1 to 7 and comparative examples 1 to 6 under the same injection conditions, and the test items for the physical properties, the light aging resistance and the antifungal properties were as follows:

tensile strength: the test is carried out according to ISO527 standard, the test speed is 50mm/min,

flexural modulus: testing according to ISO178 standard, with testing speed of 1 mm/min;

notched izod impact strength at 23 ℃: testing according to ISO180 standard, wherein the thickness of the sample strip is 4 mm;

heat distortion temperature: testing according to ISO75 standard under 0.45 MPa;

melt flow rate: testing according to ISO1183 standard under 220 deg.C/10 kg

Color difference after photoaging: photoaging experiments were performed according to SAE J2527 standard, and the color difference was measured after 2000 h.

Antibacterial and antifungal properties:

testing is carried out according to the specification of QBT 2591-2003, and the selected bacterial species are Escherichia coli and staphylococcus aureus; and calculating the bacteriostasis rate after 24h of culture according to the following formula:

R(％)＝(B-C)/B×100

in the formula: r-antibacterial ratio (%)

B-average number of recovered bacteria (cfu/patch) for blank control sample

C-average recovery bacteria count (cfu/piece) of antibacterial plastic sample

The selected mould variety is Aspergillus niger, and the grade of the long mould after 28 days of culture is divided according to the following method:

grade 0-no-length, i.e., no growth observed under microscope (50 x magnification);

level 1-trace growth, i.e. growth visible to the naked eye, but growth coverage area is less than 10%;

level 2-growth coverage is not less than 10%.

TABLE 2 comparison of Performance between examples and comparative examples

As can be seen from the results in Table 2, the AES resin composition of the present invention has the advantages of excellent antifungal effect, outstanding mechanical properties and high color retention. The resin composition can achieve the effect of resisting mildew for a long time, does not worry about the problem of color change after long-term use, has excellent mechanical properties, and well solves the problems of no pollution resistance, large color change and mechanical deterioration of the prior AES material. As can be seen from the examples 1-3 and the comparative examples 1 and 3-4, the antibacterial effects of the three synthetic organic antibacterial agents are very obvious, and are better than the inorganic metal antibacterial agent which is considered to have particularly excellent antibacterial effect in the industry at present, the mechanical properties are obviously improved, and the antibacterial effect of quaternary phosphonium salt (p-vinylbenzyltributylphosphonium chloride, A-2) is optimal; the amount of the antibacterial agent of comparative example 2 was the same as in examples 2 and 6, and was higher than in example 4; however, the antibacterial rate is lower than that of examples 1, 4 and 6, because the addition of the initiator and the crosslinking agent can initiate the reaction between the organic antibacterial agent and the AES resin, the molecular weight and the crosslinking degree of the polymer can be improved, the capability of the material for resisting the corrosion of the mold is improved, and the mold resistance is correspondingly improved. Comparing the performance data of example 2 and comparative examples 5, 6, it can be seen that: the types of the initiator and the crosslinking inhibitor have great influence on physical properties and antibacterial effect, the use temperature of the sodium thiosulfate is lower, the initiation efficiency at high temperature is not high, the degree of chain reaction of the initiated polymer at high temperature is low, so that the anti-mould effect is not obviously helped, and meanwhile, the contribution to the anti-mould effect is not great because the steric hindrance of the crosslinking inhibitor 1, 1-diphenyl-2-trinitrophenylhydrazine is great, the compatibility with materials is not high, and the effect of inhibiting crosslinking is not prominent; in addition, in the AES resin composition system, the addition amount of the synthetic organic antibacterial agent is moderate when 2-4 parts are used, and the reactive extrusion is not facilitated when the addition amount is too low or too high; the addition amount of the initiator is proper when 0.08-0.12 part, the addition amount is too low to initiate enough grafting reaction, and the anti-mildew durability of the material needs to be improved; if the amount is too high, the initiator may remain in the polymer unnecessarily, and the properties of the resin may be affected.

In conclusion, the synthetic organic antibacterial agent, the initiator and the crosslinking inhibitor with specific amounts of specific components are added into the AES resin composition, the initiator initiates free radical polymerization, so that the antibacterial group and the AES molecular chain segment are subjected to grafting reaction, the degree of the crosslinking reaction is controlled, and a series of problems of the AES resin in the prior art in the aspect of mold resistance are well solved; the AES resin composition with excellent anti-mildew effect, outstanding mechanical properties and high color retention rate is prepared; the resin composition has high efficient anti-mildew effect, can effectively improve the problems of bacterial intolerance, mildew deterioration and the like of the AES resin composition after long-term use, has high mechanical property which is higher than that of the AES resin which is not modified by anti-mildew, can meet the use requirements of most parts, has small color change after long-term photoaging, and well solves the problem of color change which is easy to occur after the resin is mixed with an antibacterial agent.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims (6)

1. The high-efficiency antifungal AES resin composition is characterized by comprising the following components in parts by weight:

the antibacterial agent is p-vinylbenzyltributylphosphonium chloride;

the initiator is dicumyl peroxide;

the crosslinking inhibitor is triphenyl phosphite.

2. The AES resin composition with high efficiency and anti-mildew property as claimed in claim 1, wherein the acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer has a core-shell structure formed by grafting acrylonitrile and styrene with ethylene propylene diene monomer as a soft core.

3. The highly effective antifungal AES resin composition as claimed in claim 1 or 2, wherein the weight average molecular weight of the acrylonitrile-ethylene propylene diene monomer-styrene graft copolymer is 50,000-200,000, the relative density is 1.0-1.04, the average diameter is 0.1-4.0 μm, the weight percentage content of the ethylene propylene diene monomer is 35-85%; the weight average molecular weight of the acrylonitrile-styrene copolymer is 100,000-500,000, and the weight percentage content of acrylonitrile is 15-40%.

4. The highly effective antifungal AES resin composition as claimed in claim 3, wherein the average diameter of the acrylonitrile-EPDM-styrene graft copolymer is in the range of 200-500 nm, and the weight percentage content of the EPDM is 60-80%; the acrylonitrile-styrene copolymer has the weight-average molecular weight of 200,000-400,000, and the acrylonitrile content is 25-35% by weight.

5. The AES resin composition with high efficiency and anti-mold property as claimed in claim 1, wherein the processing aid comprises one or more of lubricant, antioxidant and weather resistant agent; the lubricant is pentaerythritol stearate or ethylene bis stearamide; the antioxidant is hindered phenol antioxidant or phosphite antioxidant; the weather-resistant agent is a benzotriazole ultraviolet absorbent or a hindered amine free radical trapping agent.

6. A method for preparing the highly effective antifungal AES resin composition as claimed in claim 1, wherein the method comprises the steps of:

s1, weighing the raw materials according to the proportion;

s2, premixing the raw materials prepared in the step S1 in a high-speed mixer;

and S3, feeding the premix obtained in the step S2 into a double-screw extruder through a metering device, melting and compounding materials under the conveying, shearing and mixing of screws, and then carrying out extrusion, strip drawing, cooling and grain cutting to obtain the AES resin composition.