Usually the choice of additives depends on the production and processing of plastic products and the final use of the requirements, with the corresponding additives can be divided into processing aids and functional additives. Where the plastic products in the production process, can protect the resin against heat, oxygen, shear and other factors damage, or improve the resin processing additives collectively referred to as processing aids, such as antioxidants, heat stabilizers, lubricants and so on. Can be given a specific function of plastic or the use of additives known as functional additives, such as antistatic agents, anti-aging additives, flame retardants, slip agents, antibacterial agents.
The choice of plastic additives Polymer resin due to different structures show different processing characteristics, which can be divided into thermoplastic and thermosetting resin, crystalline and non-crystalline polymer. Different types of resin processing methods are different, the same type of resin and the final product uses different, processing and molding methods are different, such as: blow molding, injection molding, slush, rotomolding, casting, rolling, extrusion and so on. Similar plastic products because of its different application of the industry, the functional requirements are different, the need for functional additives are also different.
In the case of
Depending on the processing and functional selection of additives, it is often a target that corresponds to an adjuvant. The multi-performance of plastic products requires a variety of additives, but a variety of additives mixed together, the performance does not necessarily co-play sometimes anti-synergistic effect, but will deteriorate the physical properties of products, so the choice of additives should be careful The
Polyethylene wax manufacturers to remind: the use of additives, usually should follow several principles: (1) in the established formula system and processing technology, to give full play to their own efficacy; (2) does not deteriorate or minimize the basic physical resin (3) does not deteriorate or minimize the effect of other additives to play, and other additives have synergistic effect better; (4) processing thermal stability of plastic products are mostly thermoformed, should ensure that additives In the process of less loss, no deterioration, not decomposition (except foaming agent), volatile products on the processing equipment, operators and the environment harmless, that additives should be successfully passed the processing. There are many varieties of the same type of processing aids or functional auxiliaries. Not every variety is suitable for all kinds of plastics or various plastics, and some additives do not match the thermal behavior of the base resin. The mismatch of this hot behavior can lead to failure of plastic processing. Such as some engineering plastics processing in the selection of general-purpose plastic processing aids, and finally in the extruder due to decomposition of foam decomposition and difficult to shape, the function is more out of the talk; thermostat low antistatic agent used B0PP film production, the die produces a large number of irritating blue smoke, hazardous to the operating environment, product quality and performance.
Some of the additives themselves are too thermostable and may limit their function. If the decomposition temperature of the foaming agent is higher than the foaming molding temperature, the flame retardant can not generate the scavenging free radicals, the effective substances that block the reaction of the combustion chain or the active radicals when the flame retardant substrate is decomposed by heat.
Compatibility with the base resin In addition to taking into account its essential efficacy, but also from the base resin and additives structure similarity and differences to start to determine the compatibility of the two. Additives and base resin compatibility is good, it will not deteriorate (it is possible to improve) the physical properties of a substrate, but also improve resistance to migration, resistance to extraction. It is helpful to judge the compatibility of the two methods to follow the similar compatibility principle, similar structure, similar polarity, relative molecular mass and so on are conducive to the improvement of compatibility. For those additives with poor compatibility with the base resin, it is difficult to increase the amount of additives, must try to improve or improve its compatibility, such as the use of compatibilizers or coupling agent surface fine chemicals. Plastic modification and other research work has been published monographs 2, the number of related papers supporting the function of a variety of functional additives carp compound resin had to abandon the selection of modern plastic processing application activation treatment, or microencapsulation Wait.
Structures similar to the structure of synthetic resin is limited, and the structure of the additives is complicated, not each of the polymer selection additives to be selected with its similar structure, but the structure and the basic resin similar additives can improve the efficacy of additives And the overall performance of products. For example, an antioxidant 1098 with an amide structure for nylon has a much better stabilizing effect than the antioxidant 1010, and its resistance to extraction is also significantly better than that of the latter, while the antioxidant 1098 is used in polyolefins or polyesters Advantage.
The difference in the polarity of the polarity directly affects the compatibility of the additive with the base resin. Additives and matrix resin polarity does not match, resulting in poor compatibility, the performance of the physical properties of a mechanical decline, auxiliaries, surface frost, auxiliaries to shorten the durability, product discoloration, affecting the re-processing of products Wait. Therefore, non-polar or weak polar polymers should choose non-polar additives, and polar polymers should choose polar additives. For example, cationic antistatic agents for PVC, the effect is significant; and for PE or PP, then the desired effect. Another example, the production of agricultural PVC shed film drops add up to 3% to 4%; production EVA film, the amount of drops of 1.5% to 2.5%; and the production of PE film, the drop can only add 1.2 % ~ 1.8%, otherwise the surface of the film will soon produce a layer of white precipitates.
The polymer with relative molecular mass and the molecular weight of relative molecular weight is difficult to synchronize in many aspects such as dispersion behavior, melting behavior, crystallization behavior and so on, which directly affect the dispersion, migration and desorption of additives in the polymer Mentioning, but also a direct impact on the function of additives. The high molecular weight of the additive is one of the effective measures to shorten this gap and improve the compatibility. High molecular weight additives are polymerized and macromolecular type 2, such as macromolecule antioxidant 1010 than low molecular weight antioxidant 1076 hydrolysis resistance, resistance to extraction, and resin compatibility, Antioxidant function of the persistence were significantly improved. The compatibility of the polymeric hindered amine light stabilizers 944, 622, 3346, HA88, N30 and the like is superior to that of the low molecular weight monomolecular light stabilizer 770 and GW540, and the toxicity is also significantly reduced.
Improve compatibility In order to improve the compatibility of additives and resin, and sometimes must also use other measures, such as the use of coupling agent activation treatment of various types of fillers, the use of compatibilizers to improve the compatibility of different structural resins, The components are compatible and so on.
Auxiliaries of the matching plastic products in the industry to be one of the reasons for its in-depth application is its versatility. Multifunctional plastic products are by multi-species blending, eutectic molding, requiring a variety of additives do not have reactivity, a migration of additives should not lead to the loss of other additives and performance can be complementary.
Chemical resistance leads to a loss of resistance In the anti-aging auxiliaries system, hindered amines are a class of excellent light stabilizers that are superior to other types of light stabilizers, but in the case of acid flame retardants, hindered amines are generally not used Use UV absorbers. Because the acid flame retardant with the basic hindered amine light stabilizer salt reaction, leading to hindered amine failure. Similarly, there is an acidic environment problem in the acrylic wall paint. In this case, a low basic HALS can be used to react with an acidic substance, thereby exhibiting excellent anti-aging properties.
Migration caused by the loss of packaging film due to the need for composite, adhesive and smooth agent matching is critical, composite manufacturers often occur improper smooth mixing agent and adhesive, resulting in severe bonding strength attenuation, smooth performance significantly reduced problem. Because the adhesive has an inducing effect on the slip agent, accelerate the migration of the slip agent to the composite interface. Beijing Institute of Chemical Industry through the use of additives and adhesives on the relationship between the development and amide smooth agent has a better coordination of the polyurethane adhesive.
Performance complementary plastic products should not function as a simple superposition of various additives, but should be a variety of synergistic effect of synergies. A single variety of additives, sometimes not a single function. Some antioxidants (1076,168, etc.) have both light stability; some light stabilizers (such as 944) heat and oxygen stability as much as some hindered phenol antioxidant varieties (such as 1010) flame retardant synergist With smoke suppression; filler and fire resistance and so on. Some varieties with the use, can achieve synergistic effect. Therefore, the establishment of plastic products production formula, should fully consider the complementary performance of additives in order to improve the performance of the product price.
Environmental compatibility. Self-toxic and low toxicity With the continuous expansion of the field of plastic applications, especially in the food, pharmaceutical industry in-depth application, a lot of their own toxic additives were eliminated or restricted use, the application of the accident (such as burning) will produce toxic substances Of the additives (such as flame retardants) are also limited or disabled, additives non-toxic is one of the direction of development.
Reduce the environmental hazards In the plastic processing process, additives produce dust or heat generated toxic volatiles and so will harm the operator and the operating environment. The recyclability of waste plastic products and the consumption of the environment should also be the factors that must be taken into account in the selection of additives. For example, the light stabilizer GW-540 has excellent light and thermal stability, but its environmental hazards (sensitization) so that the user does not play the role of plastic additives plastic processing and functionality are mostly by adding all kinds Additives, but this does not mean that as long as the additives used properly, added to the plastic products can give full play to its effectiveness, affect the efficacy of additives to play a very complex factors.
Variety of additives and the amount of people know the amount of additives is often the more the better performance (without considering the cost of the premise) is not the case, for some additives, the increase in the amount of small, but the other properties of the product Causing significant deterioration.
The relatively low molecular weight antistatic agent has a high migration rate and can be used in a short time. However, it is used in polyolefin-based resins and has the disadvantage of poor persistence effect and is applied to the products of thermoplastic engineering plastics , Not only have a better anti-static effect, and the effectiveness of products to meet the needs.
A slight increase in the amount of slip agent, PE film will significantly increase the surface of the precipitation, resulting in faster reduction of composite bonding strength.
Processing conditions of the matching of different plastic products processing conditions, restricting the use of some additives, must be used with the processing technology to match the additives in order to pass through the processing.
For polyolefin materials (PE, PP), antistatic agents are often required to have excellent heat resistance, high safety and hygiene, and no adverse effects on the properties of the product itself. If the use of ion can not meet the above requirements, and non-ionic antistatic agent can meet these requirements, is the most commonly used polyolefin materials antistatic agent varieties.
Polyvinyl chloride (PVC), polyurethane (PU) material processing temperature is low, and the requirements of anti-static occasions often no health requirements, and high anti-static performance requirements, this time should be used cationic antistatic agent.
The antistatic effect of the cationic antistatic agent is remarkable, but the thermal stability is poor, which limits its use.
Size of the product The size of the product specifications on the performance of the auxiliary effect is mainly due to its thickness effect. In the case of an anti-aging article, a hindered amine light stabilizer is usually used in a thin product because it has no effect on the performance of the article and has no adverse effect on the properties of the article. The UV absorber thickness effect, the thinner the thickness, the effect of the worse, less used in thin film products. In the injection molding parts, while the use of hindered amines and UV absorbers, can work together. Common UV absorbers such as UV326, etc., with the hindered amine light stabilizer 770,622 and 944 with the use, can effectively improve the light stability.
For antistatic functional additives, injection molded products are often more than the film products add antistatic agent. This is mainly due to the fact that in the thicker injection molded products, the antistatic agent migrates to the surface for a long time and the relative effective concentration is low.
Use of the environment on the performance of some functional additives to play a greater impact on the environment, should be based on the right choice of appropriate varieties and the amount of the environment. Organic nonionic antistatic agents have a certain sensitivity to external humidity, which is related to their antistatic mechanism. Seasonal and regional humidity is different in the type and amount of antistatic agents must be adjusted accordingly, in order to meet the performance and price of both products to meet the needs of anti-static.
The choice of plastic additives Polymer resin due to different structures show different processing characteristics, which can be divided into thermoplastic and thermosetting resin, crystalline and non-crystalline polymer. Different types of resin processing methods are different, the same type of resin and the final product uses different, processing and molding methods are different, such as: blow molding, injection molding, slush, rotomolding, casting, rolling, extrusion and so on. Similar plastic products because of its different application of the industry, the functional requirements are different, the need for functional additives are also different.
In the case of
Depending on the processing and functional selection of additives, it is often a target that corresponds to an adjuvant. The multi-performance of plastic products requires a variety of additives, but a variety of additives mixed together, the performance does not necessarily co-play sometimes anti-synergistic effect, but will deteriorate the physical properties of products, so the choice of additives should be careful The
Polyethylene wax manufacturers to remind: the use of additives, usually should follow several principles: (1) in the established formula system and processing technology, to give full play to their own efficacy; (2) does not deteriorate or minimize the basic physical resin (3) does not deteriorate or minimize the effect of other additives to play, and other additives have synergistic effect better; (4) processing thermal stability of plastic products are mostly thermoformed, should ensure that additives In the process of less loss, no deterioration, not decomposition (except foaming agent), volatile products on the processing equipment, operators and the environment harmless, that additives should be successfully passed the processing. There are many varieties of the same type of processing aids or functional auxiliaries. Not every variety is suitable for all kinds of plastics or various plastics, and some additives do not match the thermal behavior of the base resin. The mismatch of this hot behavior can lead to failure of plastic processing. Such as some engineering plastics processing in the selection of general-purpose plastic processing aids, and finally in the extruder due to decomposition of foam decomposition and difficult to shape, the function is more out of the talk; thermostat low antistatic agent used B0PP film production, the die produces a large number of irritating blue smoke, hazardous to the operating environment, product quality and performance.
Some of the additives themselves are too thermostable and may limit their function. If the decomposition temperature of the foaming agent is higher than the foaming molding temperature, the flame retardant can not generate the scavenging free radicals, the effective substances that block the reaction of the combustion chain or the active radicals when the flame retardant substrate is decomposed by heat.
Compatibility with the base resin In addition to taking into account its essential efficacy, but also from the base resin and additives structure similarity and differences to start to determine the compatibility of the two. Additives and base resin compatibility is good, it will not deteriorate (it is possible to improve) the physical properties of a substrate, but also improve resistance to migration, resistance to extraction. It is helpful to judge the compatibility of the two methods to follow the similar compatibility principle, similar structure, similar polarity, relative molecular mass and so on are conducive to the improvement of compatibility. For those additives with poor compatibility with the base resin, it is difficult to increase the amount of additives, must try to improve or improve its compatibility, such as the use of compatibilizers or coupling agent surface fine chemicals. Plastic modification and other research work has been published monographs 2, the number of related papers supporting the function of a variety of functional additives carp compound resin had to abandon the selection of modern plastic processing application activation treatment, or microencapsulation Wait.
Structures similar to the structure of synthetic resin is limited, and the structure of the additives is complicated, not each of the polymer selection additives to be selected with its similar structure, but the structure and the basic resin similar additives can improve the efficacy of additives And the overall performance of products. For example, an antioxidant 1098 with an amide structure for nylon has a much better stabilizing effect than the antioxidant 1010, and its resistance to extraction is also significantly better than that of the latter, while the antioxidant 1098 is used in polyolefins or polyesters Advantage.
The difference in the polarity of the polarity directly affects the compatibility of the additive with the base resin. Additives and matrix resin polarity does not match, resulting in poor compatibility, the performance of the physical properties of a mechanical decline, auxiliaries, surface frost, auxiliaries to shorten the durability, product discoloration, affecting the re-processing of products Wait. Therefore, non-polar or weak polar polymers should choose non-polar additives, and polar polymers should choose polar additives. For example, cationic antistatic agents for PVC, the effect is significant; and for PE or PP, then the desired effect. Another example, the production of agricultural PVC shed film drops add up to 3% to 4%; production EVA film, the amount of drops of 1.5% to 2.5%; and the production of PE film, the drop can only add 1.2 % ~ 1.8%, otherwise the surface of the film will soon produce a layer of white precipitates.
The polymer with relative molecular mass and the molecular weight of relative molecular weight is difficult to synchronize in many aspects such as dispersion behavior, melting behavior, crystallization behavior and so on, which directly affect the dispersion, migration and desorption of additives in the polymer Mentioning, but also a direct impact on the function of additives. The high molecular weight of the additive is one of the effective measures to shorten this gap and improve the compatibility. High molecular weight additives are polymerized and macromolecular type 2, such as macromolecule antioxidant 1010 than low molecular weight antioxidant 1076 hydrolysis resistance, resistance to extraction, and resin compatibility, Antioxidant function of the persistence were significantly improved. The compatibility of the polymeric hindered amine light stabilizers 944, 622, 3346, HA88, N30 and the like is superior to that of the low molecular weight monomolecular light stabilizer 770 and GW540, and the toxicity is also significantly reduced.
Improve compatibility In order to improve the compatibility of additives and resin, and sometimes must also use other measures, such as the use of coupling agent activation treatment of various types of fillers, the use of compatibilizers to improve the compatibility of different structural resins, The components are compatible and so on.
Auxiliaries of the matching plastic products in the industry to be one of the reasons for its in-depth application is its versatility. Multifunctional plastic products are by multi-species blending, eutectic molding, requiring a variety of additives do not have reactivity, a migration of additives should not lead to the loss of other additives and performance can be complementary.
Chemical resistance leads to a loss of resistance In the anti-aging auxiliaries system, hindered amines are a class of excellent light stabilizers that are superior to other types of light stabilizers, but in the case of acid flame retardants, hindered amines are generally not used Use UV absorbers. Because the acid flame retardant with the basic hindered amine light stabilizer salt reaction, leading to hindered amine failure. Similarly, there is an acidic environment problem in the acrylic wall paint. In this case, a low basic HALS can be used to react with an acidic substance, thereby exhibiting excellent anti-aging properties.
Migration caused by the loss of packaging film due to the need for composite, adhesive and smooth agent matching is critical, composite manufacturers often occur improper smooth mixing agent and adhesive, resulting in severe bonding strength attenuation, smooth performance significantly reduced problem. Because the adhesive has an inducing effect on the slip agent, accelerate the migration of the slip agent to the composite interface. Beijing Institute of Chemical Industry through the use of additives and adhesives on the relationship between the development and amide smooth agent has a better coordination of the polyurethane adhesive.
Performance complementary plastic products should not function as a simple superposition of various additives, but should be a variety of synergistic effect of synergies. A single variety of additives, sometimes not a single function. Some antioxidants (1076,168, etc.) have both light stability; some light stabilizers (such as 944) heat and oxygen stability as much as some hindered phenol antioxidant varieties (such as 1010) flame retardant synergist With smoke suppression; filler and fire resistance and so on. Some varieties with the use, can achieve synergistic effect. Therefore, the establishment of plastic products production formula, should fully consider the complementary performance of additives in order to improve the performance of the product price.
Environmental compatibility. Self-toxic and low toxicity With the continuous expansion of the field of plastic applications, especially in the food, pharmaceutical industry in-depth application, a lot of their own toxic additives were eliminated or restricted use, the application of the accident (such as burning) will produce toxic substances Of the additives (such as flame retardants) are also limited or disabled, additives non-toxic is one of the direction of development.
Reduce the environmental hazards In the plastic processing process, additives produce dust or heat generated toxic volatiles and so will harm the operator and the operating environment. The recyclability of waste plastic products and the consumption of the environment should also be the factors that must be taken into account in the selection of additives. For example, the light stabilizer GW-540 has excellent light and thermal stability, but its environmental hazards (sensitization) so that the user does not play the role of plastic additives plastic processing and functionality are mostly by adding all kinds Additives, but this does not mean that as long as the additives used properly, added to the plastic products can give full play to its effectiveness, affect the efficacy of additives to play a very complex factors.
Variety of additives and the amount of people know the amount of additives is often the more the better performance (without considering the cost of the premise) is not the case, for some additives, the increase in the amount of small, but the other properties of the product Causing significant deterioration.
The relatively low molecular weight antistatic agent has a high migration rate and can be used in a short time. However, it is used in polyolefin-based resins and has the disadvantage of poor persistence effect and is applied to the products of thermoplastic engineering plastics , Not only have a better anti-static effect, and the effectiveness of products to meet the needs.
A slight increase in the amount of slip agent, PE film will significantly increase the surface of the precipitation, resulting in faster reduction of composite bonding strength.
Processing conditions of the matching of different plastic products processing conditions, restricting the use of some additives, must be used with the processing technology to match the additives in order to pass through the processing.
For polyolefin materials (PE, PP), antistatic agents are often required to have excellent heat resistance, high safety and hygiene, and no adverse effects on the properties of the product itself. If the use of ion can not meet the above requirements, and non-ionic antistatic agent can meet these requirements, is the most commonly used polyolefin materials antistatic agent varieties.
Polyvinyl chloride (PVC), polyurethane (PU) material processing temperature is low, and the requirements of anti-static occasions often no health requirements, and high anti-static performance requirements, this time should be used cationic antistatic agent.
The antistatic effect of the cationic antistatic agent is remarkable, but the thermal stability is poor, which limits its use.
Size of the product The size of the product specifications on the performance of the auxiliary effect is mainly due to its thickness effect. In the case of an anti-aging article, a hindered amine light stabilizer is usually used in a thin product because it has no effect on the performance of the article and has no adverse effect on the properties of the article. The UV absorber thickness effect, the thinner the thickness, the effect of the worse, less used in thin film products. In the injection molding parts, while the use of hindered amines and UV absorbers, can work together. Common UV absorbers such as UV326, etc., with the hindered amine light stabilizer 770,622 and 944 with the use, can effectively improve the light stability.
For antistatic functional additives, injection molded products are often more than the film products add antistatic agent. This is mainly due to the fact that in the thicker injection molded products, the antistatic agent migrates to the surface for a long time and the relative effective concentration is low.
Use of the environment on the performance of some functional additives to play a greater impact on the environment, should be based on the right choice of appropriate varieties and the amount of the environment. Organic nonionic antistatic agents have a certain sensitivity to external humidity, which is related to their antistatic mechanism. Seasonal and regional humidity is different in the type and amount of antistatic agents must be adjusted accordingly, in order to meet the performance and price of both products to meet the needs of anti-static.
