Improving Agents for Plastics
Plastics are used to produce a seemingly infinite array of packaging and molding materials, and manufacturers are constantly seeking ways to elicit greater performance. For a better performance and facile process an extensive variety of improving agents are used. Riken products include surfactants for food additives and ester-based plastics, all of them exceptional safe to use.
Some improving agents serve as lubricants, improving the slipperiness of plastics during molding and processing. One key application is the production of polyvinyl chloride (PVC) plastic. Because the molding and dissolution temperature levels of PVC are narrow, heat stabilizers and lubricants become essential.
Heat stabilizers for PVC chemically stabilize and prevent dissolution, while lubricants reduce the friction heat generated inside the plastic and in the molding equipment. The double-stabilizing action makes the molding process easier, improving both productivity and the appearance of the final product.
Two Riken Vitamin lubricants, Rikemal and Rikester, are fatty acid ester lubricants which boast excellent safety. In stabilizers, Riken Vitamin has recently enjoyed solid growth in zinc-calcine stabilizers, thanks to their low environmental impact.
One of our fatty acid ester lubricants, Rikester, is exceptionally effective in lubricating the surface between the metal of the molding equipment and the plastic itself. This product is gaining considerable industry attention as a lubricant that works well with zinc-calcine stabilizers.
As the search for environmentally friendly compounds intensifies, Riken Vitamin expects the demand for these lubricants to surge. Applications are in e.g. molding of seats, pipes and a host of other products.
In addition, Rikemal and Rikester are used as lubricants in the production of polyolefin plastics, polystyrene plastics, polyamide plastics and engineering plastics.
|Pipe||Profile, Sheet||Bottle||Film||Extrusion||Calen- dering|
|Organic acid ester of monoglycerides|
|Specialities of fatty acid esters||✓||✓||✓||✓||✓||✓||✓|
|Higher alcohol fatty acid esters||✓||✓|
Releasing Agents and Anti-Blocking Agents
Whereas lubricants mainly act during the melting of plastics, releasing agents and anti-blocking agents are normally applied during and after cooling.
Releasing agents facilitate separation of plastic casts from the metal mold in the extrusion process.
Anti-blocking agents play a similar but distinct role, preventing plastic sheets and films from sticking to the mold.
Riken Vitamin's Rikemal and Rikester improve the plastic surface to generate the releasing and anti-blocking effects.
|Releasing agents and Anti-blocking agents||PP||PC||PS||ABS||POM||PMMA||PBT||PET||SAN|
|Sorbitan fatty acid esters||✓|
|Specialities of fatty acid esters||✓||✓||✓||✓|
|Higher alcohol fatty acid esters||✓||✓||✓|
Static electricity is generated when different materials come into contact, rub against each other or are separated. Because surfaces of plastics are hydrophobic, static electricity is difficult to disspate and tends to stay where generated. Static electricity may cause damaging results as it attracts dust onto the packaging material or product, causes electricity discharge during molding and results in office-automation equipment malfunction. Anti-static agents are used to prevent all of these ill-effects.
Anti-static agents such as Rikemal and Rikemaster, which are kneaded in the plastics offer a hydrophilic surface, sharply reducing the potential for staticelectricity generation. One of the key ingredients for Riken ́s anti-static agents is the highly safe glycerol fatty acid ester.
Rikemal and Rikemaster anti-static agents include instantaneous anti-static agents, which start preventing static electricity as soon as molding is complete; continuous antistatic agents, which maintain the antistatic effect over long periods of time; anti-static agents that are especially effective on laminate films; and antistatic agents that reduce printing jams in waterbased-ink printers.
Rikemal and Rikemaster are used to produce a wide spectrum of plastics, including rigid PVC plastic, polyethylene plastic, polypropylene plastic, polystyrene plastic and polyethylene terephthalate plastic.
|Organic acid esters of monoglycerides|
|Polyglycerol faty acid esters||✓|
Sudden and rapid changes in ambient temperature or humidity can cause fine water droplets to be adsorbed on the surface of plastics, interrupting the passage of light. In film application such as food wrapping among others, fogging may block the view towards the wrapped food. Moreover, the adsorbed water droplets can cause rust and food spoilage. When transparent films are used in agricultural applications such as greenhouses and “greentunnels”, any decrease in light transmittance has a negative impact on crop growth, while deposition of water droplets can propagate crop blight. Because plastics are designed to repel water using a hydrophobic surface, adsorption of water droplets causes fogging. Anti-fogging agents provide a means of preventing this anti-fogging effect.
Riken Vitamin's anti-fogging agents, Rikemal and Rikemaster, are applied by either kneading (in the plastic material) or coating (onto the molded product), changing the hydrophilic properties of the plastic surface.
Any adsorbed water droplets become a uniform film of water, eliminating clouding and improving the plastic's transparency.
Rikemal and Rikemaster are highly safe products, thus used as key components (glycerol fatty acid esters, polyglycerol fatty acid esters and sorbitan fatty acid esters) in plastics for food contact. Riken Vitamin also produces a coating-type antifogging agent for food containers, called Rikemal A.
In agricultural films, Riken Vitamin offers a composite formula that applies our company's surfactant technology. This formula is used to produce long-term antifogging agents, which maintain their antifogging effect for remarkably extended periods. Other anti-fogging agents are designed to suppress excessive moisture bleed-out. Rikemal and Rikemaster are widely used in stretch films, agricultural films and rigid sheets.
|Anti-fogging agents||PVC||PP||LDPE &
|Food wrap||Agricul- tural film||Rigit film||CPP||BOPP||Food wrap||Agricul- tural film||Food wrap||Agricul- tural film||OPS||A-PET|
|Organic acid esters of monoglycerides|
|Polyglycerol faty acid esters||✓||✓||✓||✓||✓||✓|
|Sorbitan fatty acid esters||✓||✓|
|Specialities of fatty acid esters|
Plasticizers are additives helping the flexibility of a usual rigid product. Riken ́s plasticizers are a highly safe plasticizer that meets government standards for food additives, and is deployed in a wide assortment of applications.
BIOCIZER is a general-purpose plasticizer. It can be used in all standard plastic-manufacturing processes, including calender, extrusion, injection molding and paste formation. Plasticizers are expected to grow and find broader application than ever in the near future, as these remarkable agents are applied to PVC, acryl-pastosol and adhesives. They may even be used to lend flexibility to materials that were previously rarely used, such as urethane plastics.
One class of plasticizers expected to enjoy widespread use going forward is represented by Rikemal PL-019 and Rikemal PL-710. These two plasticizers are compatible with polylactide plastics, which are derived from plant fiber, and are therefore useful in making these rigid plastics supple and improving their workability. Effects of these plasticizers include rendering molded products flexible, improving impactresistance, improving molding workability by promoting crystallization during the molding process, and eliminating film crackle.
One difficulty with polylactide plastics is their crystalline nature. When crystalline plastics are softened in combination with a plasticizer, their glass transition point (Tg) drops. If Tg falls to near room temperature, transparency declines as crystallization gradually progresses, and changes to molding characteristics, such as an increase in modulus (hardness). Before these materials can be plasticized, measures must be devised to overcome this problem.
At Riken Vitamin, we applied a technology that regulates crystal formation in polylactide plastics at the nanoscale level. With this innovation, we successfully combined polylactide plastics with plasticizers to develop a flexible polylactide compound.
As a breakthrough achievement of making polylactide plastics supple while maintaining excellent transparency, Riken Vitamin created a new class of plastics. We expect these materials to be adopted in a wide
range of use, including food packaging films, agricultural films and others.
|Food wrap||Plastisole||Cap seal||Sheet|
Plastics can be combined with inorganic substances and fillers, but if the compatibility between the plastic and other materials is poor, problems of dispersion, such as condensation and flaking can occur.
Dispersants are used to disperse these non-plastic components evenly throughout the plastic. One example: A flame retardant is applied to a surface to improve the plastic's flame-resistance.
However, the flame retardant is a relatively highly polarized material, while plastics such as olefin have low polarization.
The result: the flame retardant does not mix well with the plastic.
Our product, Rikemal applies a unique surfactant technology to powerfully disperse the inorganic substance uniformly throughout the plastic.
|Polyglycerol fatty acid esters||✓||✓|
|Sorbitan faty acid esters||✓||✓||✓||✓||✓|
Anti-oxidants are used to suppress damage to plastics by oxidation, which can occur during and just after molding. A wide range of anti-oxidants are available today on the market.
Riken Vitamin's range of anti-oxidant products is the Riken E Oil-Series based on Vitamin E (Tocopherol). The Riken E Oil Series is widely used in plastic containers for food packaging.