Silanes for Adhesives

  Nanjing Aocheng Chemical Co.,LTD is a supplier  of silane , let's introduce the silane adhesion promoters are as follows:

Silane adhesion promoters are bifunctional organosilicone compounds which act as molecular bridges between the polymer matrix of an adhesive or sealant and the substrate, either inorganic or organic.

The silane end contains hydrolysable alkoxy groups that are activated by reaction with ambient moisture. The hydrolysable alkoxy groups attached to the silicon end of the silane are typically either methoxy or ethoxy. Once activated (hydrolyzed), the resultant silanol groups will condense with o ther silanols or with reactive groups on the surface of a substrate such as SiOH, AIOH, or other metal oxides or hydroxides.The silane’s ability to bond to a surface will generally be determined by the concentration of such sites on the surface. Selecting the optimal silane for an application requires matching the reactivity of the silane‘s organofunctional group to that of the polymer.

The silanes can be blended into an adhesive formulation or used as primers on substrates. The structure and re activity of the silane will affect the ability of the silane to migrate. The most effective way to promote adhesion is to apply the silane as a primer to the surface, followed by application of the adhesive/sealant.

In this way, the silane will be on the s urface and therefore at the interface where it can enhance adhesion between the polymer and the substrate. Silane primers are usually dilute solutions of 0.5 to 5 percent silane in alcohol or water/alcohol solvent. They are wiped or sprayed on the substrate, after which the solvent is allowed to evaporate. While the concentration needed for a specific application may vary, one percent (1%) based on resin content is recommended as a good starting point.

The organofunctional group of the silane can react, and bond to, the polymer backbone. Residual moisture activates the silane’s alkoxy groups to the active silanol form which react with each other, liberating
moisture, and forming siloxane bonds between the polymers. The resulting Si-O-Si crosslink is extremely durable, offering excellent weather, UV, temperature, chemical and moisture resistance.

The filler may either be treated with silane before it is added to the sealant formulation (pretreatment method), or it can bind with the filler during compounding (additive method).

Alkoxysilanes react very rapidly with water;they are usually used to capture excess moisture in sealants and adhesives.

Vinyltrimethoxysilane is the most common moisture scavenger , due to the electron interactions of the vinyl group it reacts with moisture faster than other alkoxy silanes, enabling it to function as a moisture scavenger in the presence of other silanes incorporated as adhesion promoters, crosslinkers or coupling agents. The amount of silane added will depend on the water content of the formulation constituents.

Methanol is formed as a byproduct, and the vinyl silane crosslinks into an inactive species in the formulation. Other alkoxy silanes, such as methyltrimethoxysilane, are also used as waters.
 

(source:http://www.ac-chem.net/news/silanes-for-adhesives-8e0b.html)

Silanes as Primers and Adhesion Promoters

Organosilanes are "molecular bridges" that are used as primers and adhesion promoters for coatings or adhesives. The addition of a silane at the interface results in high bond strength and corrosion resistance. The chemical link created by the use of a silane contributes various benefits, such as:

• A strong bond between the inorganic surface and the organic polymer to provide enhanced adhesion in both wet and dry environments;
• a barrier to prevent moisture penetration through the interface;
• improved bulk physical properties of the coating or adhesive through enhanced adhesion between the polymer and the filler particles within the formulation and the efficient transfer of stress from the resin to the filler;
• effective dispersion of fillers and reduction in the apparent viscosity of the system.

Silanes are a group of specialty organo functional compounds that possess dual reactivity. The silanes act chemically with both the metal substrate and the organic base polymer in the coating or adhesive.The silane adhesion promotes and protects the metal substrate by forming covalent bonds across the interface that are both strong and durable.

Silanes can be applied directly to the substrate, similar to conventional primers, or they can be mixed into the coating or adhesive formulation as an additive. Optimum results are generally achieved by using the silane as a substrate primer. When applied directly to the substrate, they are very thin coatings only about one monolayer in thickness. When mixed with the coating, the coupling agent is capable of migrating to the interface and reacting with the substrate surface as the coating or adhesive dries.

Over the last 20 years, the silane adhesion promoter marketplace has evolved to include a plethora of materials of which organosilanes have secured a prominent position. The choice of a particular silane will depend on the specific formulation of the coating or adhesive, on the substrate and on the method of application.

Optimizing the potential properties of silane systems offers a challenge.There are many parameters that can effect the performance of silane. Therefore, it is recommended that the silane supplier be contacted to assist in making a selection.

Silanes are multifunctional in that they can be used to promote crosslinking, and they can be incorporated directly into a polymer chain by various reaction mechanisms. In addition to coatings and adhesives, silanes have multiple commercial uses, such as coupling agents for reinforced plastics, crosslinking agents for polyethylene cables, and dispersants for paints and printing inks.

(source:http://www.ac-chem.net/news/silanes-as-primers-and-adhesion-promoters-b75e.html)

Silane adhesion promoters

A model polyurethane (PUr) adhesive has been modified by the addition of various silane adhesion promoters and used to bond PVC, ABS, a polyblend and glass. Inverse gas chromatography (IGC) data showed that epoxy silane substantially increased the surface reactivity of the adhesive while maintaining its amphoteric character. An aminosilane shifted the PUr surface to basicity, while vinyl, mercapto and chlorosilanes promoted surface acidity. Lap-shear data identified the amphoteric epoxy silane as the most successful adhesion promoter in all polymer and glass assemblies, increasing their initial bond strengths and also their residual bond strengths following accelerated aging. Elsewhere, the success of silane additives reflected the strength of interfacial acid/base interactions, the aminosilane being favored for bonding PVC, the others being preferred for the basic ABS and polyblend substrates. Correlations were developed between residual bond strength and initial bond properties of the assemblies and also between these system characteristics and an acid/base interaction parameter. The correlations may be useful as guidelines to the formulation of superior adhesives for bonding with substrates of known acid/base interaction potential.

silane in fiberglass

1. Glass fiber surface treatment Objective and Significance
　　Surface treatment is a processing which use the treating agent to cover the surface of reinforcement.These treating agents include treating compound, some of silane coupling agent and auxiliaries. It helps forming a well bond surface between reinforcement and substrate and also can improve various properties of compound materials.
　　Significance of treatment: We know that function of compound materials are not only related with content and property of resin and fiber, but also greatly depend on the bond of resin and fiber. Surface treatment includes interface processing which is coating a called “surface treatment agent” on the surface of glass fiber. This agent could solidly combined fiber and resin so as to increase the function of glass.
　　
2. Silane coupling agent and their reaction theories.
　　Silane coupling agent is this kind of materials which are usually have two different groups on
themselves ends. One end’s groups have the chemical action or physics action with the surface of
reinforcement, while the other end’s groups can react with base materials, so that well bond the
reinforcement with substrate to get the good bonding between interfaces and improve many respects of functions and effectively resist water.
　　Organic-functional silane is a kind of surface treating agent with many different and effective kinds and it’s normal chemical structure is RnSiX4-n.
There are four steps to treat fiber glass with Organic functional Silane coupling agent:
1. First, there are three unreliable X groups in atom Si to hydrolyze
2. Second, the silane coupling agent condensate Oligomers
3. Third, those oligomers formed hydrogen bond with the “–OH” group of the glass fiber surface
4. Last, In the process of drying and curing, silane creates covalent bonds with glass fiber surface.

3. Glass fiber surface processing method and factors.
　1. The treatment method of silane coupling agents for the surface of fiberglass:
　（1）Post-treatment （2）Pre-treatment （3）Grafting
Most of silanes are used in treating compound of fiberglass. We will mainly introduced pre-treatment.
　　Changing the formula of treating compound appropriately, it is not only meet the requirements of fiber forming, spinning and other process, but also not hinder the infiltrating and adhesion between the resin matrix and fiberglass. And also not hinder resin base material wetting and sticking on glass fiber. In the process of fiber forming, we add the silane coupling agent into the treating compound which make the surface treating agent coated on the surface of fiberglass, and we call this process is pre-treatment, which is weaving fiber cloth with fiber which is covered by reinforced treating compound.
  2. The dosage of silane coupling agent and factors of treatment.
　a. The dosage of silane coupling agent
　　Playing the role in silane coupling agent is the micro-quantity of monolayer of silane coupling agent. And the appropriately dosage of each kind of silane is result from the experiment.
Attention: the dosage of silane coupling agent can calculate:
Computing method: V2/ V1 = M
V1: The minimum coating area of 1g silane coupling agent
V2: The surface area of 100g reinforced materials
M: The required quantity of silane coupling agent to coat a monolayer in 100g treated materials.
b. Factors of treatment:
1) The dosage of silane coupling agent
2) The temperature and time of drying
3) The pH value of treatment compound

5. Requirements on silane coupling in fiberglass industry
a. Silane coupling must be dispersed in water, because the wetting agent of fiberglass adopts water as the carrier;
b. Purity of silane coupling should be higher, such as AC-220 requires the purity is higher than 98%; if the content is low and foreign substance is too much, the strength of the compound materials will change greatly;
C. The hydrolysis rate is required to be within 30 min, affecting the production efficiency of wetting agent.
d. It can improve the strength and electric properties, etc. of fiberglass reinforced resin.

(source:http://www.ac-chem.net/news/Silane-in-Fiberglass-8a3a.html)

Typical Silane Applications

Silane Coupling Agent: Organofunctional alkoxysilanes are used to couple organic polymers to inorganic materials. Typical of this application are reinforcements, such as fiberglass and mineral  fillers, incorporated into plastics and rubbers. They are used with both thermoset and thermoplastic systems. Fiberglass applications include auto bodies, boats, shower stalls, printed circuit boards, satellite dishes, plastic pipes and vessels, and many others. Mineral-filled systems include reinforced polypropylene, silica-filled molding compounds, silicon-carbide grinding wheels, aggregate-filled polymer concrete, sand-filled foundry resins, clay-filled EPDM wire and cable, clay- and silica-filled rubber for automobile tires, shoe soles, mechanical goods and many other applications.

Silane Adhesion Promoter: Silane coupling agents are effective adhesion promoters when used as integral additives or primers for paints, inks, coatings, adhesives and sealants. As integral additives, they must migrate to the interface between the adhered product and the substrate to be effective. By using the right silane coupling agent, a poorly adhering paint, ink, coating, adhesive or sealant can be converted to a material that often will maintain adhesion even if subjected to severe environmental conditions.

 Hydrophobing and Dispersing Agent: Alkoxysilanes with hydrophobic organic groups attached to silicon will impart that same hydrophobic character to a hydrophilic inorganic surface. They are used as durable hydrophobing agents in construction, bridge and deck applications. They are also used to hydrophobe inorganic powders to make them free-flowing and dispersible in organic polymers and liquids.

Silane Crosslinking Agent: Organofunctional alkoxysilanes can react with organic polymers to attach the trialkoxysilyl group onto the polymer backbone. The silane is then available to react with moisture to crosslink the silane into a stable, three-dimensional siloxane structure. Such a mechanism can be used to crosslink plastics, especially polyethylene, and other organic resins, such as acrylics and urethanes, to impart durability, water resistance and heat resistance to paints, coatings and adhesives.

Silane Moisture Scavenger: The three alkoxy groups on silanes will hydrolyze in the presence of moisture to convert water molecules to alcohol molecules. Organotrialkoxysilanes are often used in sealants and other moisture-sensitive formulations as water scavengers.

Polypropylene Catalyst “Donor”: Organoalkoxysilanes are added to Ziegler-Natta catalyzed polymerization of propylene to control the stereochemistry of the resultant polypropylene. The donors are usually mono- or di-organo silanes with corresponding tri- or di-alkoxy substitution on silicon. By using specific organosilanes, the tacticity and properties of the polypropylene are controlled.

Silicate Stabilizer: A siliconate derivative of a phosphonate-functional trialkoxysilane functions as a silicate stabilizer to prevent agglomeration and precipitation of silicates during use. The predominant application is in engine coolant formulations to stabilize the silicate corrosion inhibitors.

(source:http://www.ac-chem.net/news/typical-silane-applications-80ac.html)

Silane coupling agents

Silane coupling agents are silicon-based chemicals that contain two types of reactivity–inorganic and organic–in the same molecule. A typical general structure is (RO)3SiCH2CH2CH2-X,where RO is a hydrolyzable group, such as methoxy, ethoxy, or acetoxy, and X is an organofunctional group, such as amino, methacryloxy, epoxy, etc.
A silane coupling agent will act at an interface between an inorganic substrate (such as glass, metal or mineral) and an organic material (such as an organic polymer, coating or adhesive) to bond, or couple, the two dissimilar materials.
A simplified picture of the coupling mechanism is shown in Figure 1.

(source:http://www.ac-chem.net/news/Silane-Coupling-Agents-9338.html)

silane crosslinking agent

Silane crosslinkers AC-271 is one of the silane crosslinking agent,it has many features as follows:

Properties

Pipes and cables produced from silane-crosslinked polyethylene (PE-Xb) using AC-271 are more resistant to heat and weathering than products made from non-crosslinked polyethylene. They also have improved electrical properties. The storage stability is greatly enhanced in formulations of silane crosslinking adhesives and sealants.

Use of AC-271 as a co-monomer in polymer dispersions results in binders which exhibit much improved wet scrub resistance and higher abrasion resistance thanks to crosslinking and improved adhesion to the substrate.


Applications

Silane AC-271 is an essential ingredient in many industries as below:

Moisture curing of polymers: For the preparation of moisture-curing polymers  

Adhesion promotion & surface modification: As an efficient adhesion promoter for various mineral-filled polymers

As co-monomer for polymer dispersions: Improve adhesion strength in wet conditions and scrub resistance

As moisture scavenger: Can react rapidly with water

Other applications: can easily bond with OH-group. Hydroxyl containing polymers; it is activated by its proximity to silicon

3-Methacryloxypropyltrimethoxysilane

A series of poly(3-methacryloxypropyltrimethoxysilane)/waterborne polyurethane (PMPS/WPU) composite latexes and organic–inorganic hybrid films with PMPS contents of 0, 10, 20, 30, 40 and 50 wt.% were prepared via seeded emulsion polymerization initiated by AIBN and hydrolysis–condensation process of PMPS during the evaporation of water, respectively. WPU, that is anionic polyurethane emulsion, was synthesized using isophorone diisocyanate, polytetramethylene ether glycol, dimethylol propionic acid, 1,4-butanediol, and triethylamine. An investigation of transmission electron microscopy confirmed the core–shell morphology of the composite latex particle which was composed of a PMPS core and a polyurethane shell. A dynamic light scattering analysis showed that the average particle size distributed in the range of 42–134 nm. The proposed novel preparation method included the use of polyurethane as macromolecular emulsifier and steric stabilizer, control of (3-methacryloxypropyltrimethoxysilane) (MPS) content less than 50 wt.%, slow addition of MPS and application of AIBN ensured the preparation of a stable PMPS/WPU composite latex. Formed PMPS/WPU organic–inorganic hybrid film with high PMPS content via sol-gel process had uniform transparency at visible band because of less crystalline and phase separation between organic and inorganic phases.

Silane crosslinkers

Titanates provide functionality to a multitude of polymers – such as carbonates, sulfur, sulfur donors,sulphates, nitrides, nitrates etc.
They are suitable silane crosslinkers,providing plastics, resins and coatings(inks) with better solvent resistance,weathering, electrical and di-electric properties.
By choosing the proper titanate, this might allow formulators to design waterborne coatings with performance levels, close to solvent based coatings.Titanates crosslink cellulose or water soluble polymers to control the thixotropy of a waterborne coating.
Treated minerals and pigments can be dispersed easily in the polymer matrix, both in aqueous and nonaqueous systems while reducing system viscosity. For plastics and rubber, titanate treated minerals and fillers can increase compounding rates while reducing process  temperatures. With high use levels of certain minerals, like Al(OH)3 or Mg(OH)2 etc. titanates can improve flame retardant properties without using halogens contain compounds.Titanate treated iron oxides can make better plastic / rubber magnets.

Silane Crosslinking Agent

The PEX-b method of producing PEX piping, often referred to as silane crosslinking agent technology or the moisture crosslinking process, originated in the Wire & Cable industry as a means of insulating metal conductors. Moisture-induced silane crosslinking agent technology was designed to replace PE compounds that were soaked in peroxide and then crosslinked by extrusion through a steam or molten salt vulcanization tube. This vulcanization process is not entirely unlike some current PEX-a process technologies used to produce PEX tubing.

PEX-b has been the fastest growing segment in the production of PEX piping due to its relatively low capital investment in comparison to PEX-a and PEX-c methods. A standard thermoplastic pipe extrusion line combined with a post-extrusion hot water treatment apparatus to flush and crosslink the tubing allowed a pipe manufacturer to enter the fast growing PEX market using Sioplas™ process technology. Invented and patented by Dow Corning in 1968, the Sioplas process extrudes tubing pipe from a reactive compound composed of silane groups which have been grafted onto PE polymer chains Ribarits . This is accomplished by a custom compounder who grafts the silane onto an HDPE by adding organic peroxide in a high temperature compounding, extrusion and pelletizing process. This reactive compound, when combined with a tin catalyst masterbatch and extruded into tubing by the pipe manufacturer, will the crosslink in PEX tubing after being flushed with hot water.

An alternate technology for PEX-b tubing production is referred to as the Monosil™ process and was developed jointly by Maillefer and BICC in 1974 as a one-step-process, where all of the components of PE base resin, additives, peroxide and silane are grafted in a specialized compounding extruder which also extrudes the pipe in-line Ribarits . Like the Sioplas technology, the Monosil technology also requires a post-extrusion treatment that flushes hot water through the pipe to initiate the crosslinking reaction.

3-Aminopropyltriethoxysilane

We demonstrate that a 3-aminopropyltriethoxysilane-treated glass surface is superior to an untreated glass surface for coating with extracellular matrix (ECM) proteins when used as a cell culture substrate to observe cell physiology and behavior. We found that MDCK cells cultured on untreated glass coated with ECM removed the coated ECM protein and secreted different ECM proteins. In contrast, the cells did not remove the coated ECM protein when seeded on (3-aminopropyl)triethoxysilane-treated (i.e., silanized) glass coated with ECM. Furthermore, the morphology and motility of cells grown on silanized glass differed from those grown on non-treated glass, even when both types of glass were initially coated with laminin. We also found that cells on silanized glass coated with laminin had higher motility than those on silanized glass coated with fibronectin. Based on our results, we suggest that silanized glass is a more suitable cell culture substrate than conventional non-treated glass when coated by ECM for observations of ECM effects on cell physiology.

silane adhesion promoters

The effects of an ammonia-based catalyst, surface coverage, organofunctional group and chain length on silane adhesion promoters efficacy were examined at a benzocyclobutene (BCB)/silicon dioxide interface with silanes of varying functionality and chain length. Fracture-mechanics-based techniques, and X-ray photoelectron spectroscopy and contact-angle measurements were used to quantify the adhesion energy and silane surface coverage, respectively. Inclusion of a propylamine catalyst in silane solutions was found to affect both silane surface coverage and the resulting adhesion energy. However, in the absence of the catalyst comparable results were obtained with hydrolysis times in excess of 1 h. Only a weak dependence of adhesion energy on silane surface coverage was observed. After adhesion energy results for silanes with varying organofunctional group were normalized for differences in surface coverage, only the vinylfunctional silane was found to enhance adhesion of BCB to silicon dioxide, due to interaction of the vinylfunctional group with BCB during cure. A trend of increasing adhesion energy with increasing chain length was observed for CH3-terminated silanes (2 n 18), while an opposite trend of decreasing adhesion energy with increasing chain length was found for vinyl-terminated silanes (2 n 22). The results are compared to existing models of polymer chain entanglement.

adhesion accelerator

The use of adhesion accelerators and activators lowers the activation energy of vulcanization reaction to 80-125kJ/Mole from 210kJ/Mole which is necessary if we use ‘Sulphur’ alone. Adhesion accelerators and activators break sulphur chains. Accelerated sulphur vulcanization systems require only 5-15 sulphur atoms per cross-link as compared to 40-45 S atoms/crosslink for a non-accelerated sulphur vulcanization. There are many  adhesion  accelerators available for the vulcanization of rubber. That is because there is a wide range of rubber articles on the market with a wide variety of properties. For instance in a car tire alone there can be already up to eight different rubber compounds, each with specific properties. For instance the tread in a typical passenger car tire consists of a mixture of SBR (styrene-butadiene rubber) and BR (butadiene rubber). This rubber should have high abrasion resistance and high grip on both dry and wet roads. The side wall of the tire should have a high flexibility, meaning that it should resist many flexings during the running of the tire without cracking. It consists normally of a mixture of natural rubber and butadiene rubber. Inside the tire there is a rubber compound with as major function the adhesion between rubber and the steel cord of the belt. It typically consists of natural rubber with a very high sulfur level (up to 8 phr), to get a relatively stiff rubber, with sulfur promoting the adhesion with the steel cord. The basis of the tire is formed by the carcass, normally a mixture of NR (natural rubber), SBR and BR. It should have a very good adhesion to the polyester cord, used as reinforcement. And the inner side of the tire is formed by the inner liner, normally consisting of halogenated butyl rubber (IIR) For all these compounds with their different properties different
adhesion accelerators and mixtures of adhesion accelerators have to be used to obtain the required properties. A vulcanization  adhesion  accelerator is typically used in combination with sulfur as the cross-linker, and with zinc oxide and stearic acid as activators. Other additives can be added too, but for the cross-linking reaction the abovementioned ones are the most important. The various types of rubber used in the various tire compounds all have different vulcanization characteristics, like speed of cure (cure is the crosslinking reaction) and extent of cure (the number of cross-links). A typical passenger car tire is vulcanized for 10 minutes at 170 degrees C. This means that all the different compounds have to be cured to their optimum state of cure in this same 10 minutes. This is the reason why a lot of different adhesion accelerators or mixtures thereof are used in the same tire.

Silane adhesion promoters

Silane adhesion promoters are bifunctional organosilicone compounds which act as molecular bridges between the polymer matrix of an adhesive or sealant and the substrate, either inorganic or organic.

The silane end contains hydrolysable alkoxy groups that are activated by reaction with ambient moisture. The hydrolysable alkoxy groups attached to the silicon end of the silane are typically either methoxy or ethoxy. Once activated (hydrolyzed), the resultant silanol groups will condense with o ther silanols or with reactive groups on the surface of a substrate such as SiOH, AIOH, or other metal oxides or hydroxides.The silane’s ability to bond to a surface will generally be determined by the concentration of such sites on the surface. Selecting the optimal silane for an application requires matching the reactivity of the silane‘s organofunctional group to that of the polymer.

The silanes can be blended into an adhesive formulation or used as primers on substrates. The structure and re activity of the silane will affect the ability of the silane to migrate. The most effective way to promote adhesion is to apply the silane as a primer to the surface, followed by application of the adhesive/sealant.

In this way, the silane will be on the s urface and therefore at the interface where it can enhance adhesion between the polymer and the substrate. Silane primers are usually dilute solutions of 0.5 to 5 percent silane in alcohol or water/alcohol solvent. They are wiped or sprayed on the substrate, after which the solvent is allowed to evaporate. While the concentration needed for a specific application may vary, one percent (1%) based on resin content is recommended as a good starting point.

The organofunctional group of the silane can react, and bond to, the polymer backbone. Residual moisture activates the silane’s alkoxy groups to the active silanol form which react with each other, liberating
moisture, and forming siloxane bonds between the polymers. The resulting Si-O-Si crosslink is extremely durable, offering excellent weather, UV, temperature, chemical and moisture resistance.

The filler may either be treated with silane before it is added to the sealant formulation (pretreatment method), or it can bind with the filler during compounding (additive method).

Alkoxysilanes react very rapidly with water;they are usually used to capture excess moisture in sealants and adhesives.

Vinyltrimethoxysilane is the most common moisture scavenger , due to the electron interactions of the vinyl group it reacts with moisture faster than other alkoxy silanes, enabling it to function as a moisture scavenger in the presence of other silanes incorporated as adhesion promoters, crosslinkers or coupling agents. The amount of silane added will depend on the water content of the formulation constituents.

Methanol is formed as a byproduct, and the vinyl silane crosslinks into an inactive species in the formulation. Other alkoxy silanes, such as methyltrimethoxysilane, are also used as waters.

Adhesion Accelerator

A method of improving the bonding of vulcanized rubber to metal, in which the improvement is characterized in an adhesion accelerator comprising at least one nickel organic compound selected from the group consisting of Ni-containing soaps having carboxylic acid moieties each having 6 to 30 carbon atoms in its main chain, or a mixture thereof, an organic boron complex containing Ni bonded to a carboxylic acid moiety having 6 to 30 carbon atoms in its main chain, and Ni-acetyl acetonate, and at least one zinc organic compound selected from the group consisting of Zn-containing soaps having carboxylic acid moieties each having 6 to 30 carbon atoms in its main chain, or a mixture thereof, an organic boron complex containing Zn bonded to a carboxylic acid moiety having 6 to 30 carbon atoms in its main chain, and Zn-acetyl acetonate, blended together to have a Ni/Zn weight ratio of from 0.01 to 20, being added in an amount of 0.1 to 10 parts by weight, based on 100 parts by weight of the rubber component, to a rubber component and 3 to 8 parts by weight of sulfur, based on 100 parts by weight of the rubber component, prior to the vulcanization thereof.

Resin Modifier

In resin  systems, additives adapt the base resins for particular applications and, thus, help differentiate products in the marketplace. Sometimes known as modifiers — a class distinction more descriptive of their function — they variously alter or fine-tune one or more of the system’s native processing or performance attributes.

Additive suppliers cite several trends in additive product development. One is sustainability. With an eye to increased regulatory scrutiny, many new developments have been stimulated by a desire for renewable content that is green (bio-derived) or recycled/recyclable. Another trend is a preference for reengineering. Salvatore Monte, president of Kenrich Petrochemicals Inc. (Bayonne, N.J.), says that to reduce regulatory exposure and product-development costs, many companies prefer to rework an existing product rather than develop a new one. He draws a parallel to the pharmaceuticals industry.

“Like drugs, additives are now subjected to a much more rigorous global registration process than just three decades ago — and the amount of time and toxicology study costs involved really require a ‘killer app’ that will justify the investment in a really new additive. So, blends, hybrids and new combinations and applications of existing additives will trump truly ‘new’ materials — unless a new additive is so disruptive that it cannot be held back because ever-increasing performance demands require its use.”

What’s clear is that both new and renewed resin modifiers are breaking new ground in process and part-performance optimization.