Isosorbide Diester Plasticizer Mixture for PVC
Solution Overview
Problem
Current plasticizers for PVC, such as phthalic acid esters, are largely based on fossil resources and have health and environmental concerns, necessitating the development of alternatives that are more sustainable and effective.
Innovation Solution
A mixture of diesters of dianhydrohexitol derivatives, particularly isosorbide diesters, with carboxylic acids containing at least two structurally different nonanoic acids, offering improved miscibility, low-temperature flexibility, and biodegradability, which are produced through a specific process involving hexavalent alcohols and acidic ion exchange resins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If single isomer nonanoic acids (pelargonic acid or 3,5,5-trimethylhexanoic acid) are used to produce isosorbide esters, then the production process is simple, but the resulting esters have poor miscibility with PVC and limited plasticizer performance
Solution Approach 1:
The patent combines multiple isomeric nonanoic acids (at least two different isomers) into a mixture before esterification with isosorbide. This merging of different acid isomers creates a mixed diester product that achieves superior miscibility with PVC and enhanced plasticizer performance compared to esters from single isomers, while maintaining manufacturing simplicity.
2Temperature
If esters with high branching degree are used to improve low-temperature flexibility, then low-temperature properties improve, but viscosity increases and miscibility with PVC deteriorates
Solution Approach 1:
The patent applies local quality by using a mixture of nonanoic acid isomers with different branching degrees rather than a single highly branched isomer. The mixture contains isomers with varying structural characteristics (some with higher branching for low-temperature flexibility, others with lower branching for lower viscosity and better miscibility), creating a balanced plasticizer with optimized local properties throughout the molecular structure.
3Temperature
If highly branched nonanoic acid isomers are used to enhance low-temperature properties, then low-temperature flexibility improves, but the miscibility with PVC and flowability deteriorate
Solution Approach 1:
The patent merges multiple nonanoic acid isomers with different branching characteristics into a single plasticizer formulation. This combination allows the highly branched isomers to provide low-temperature flexibility while the less branched isomers maintain miscibility with PVC and ensure good flowability, achieving a balance that no single isomer could provide alone.
4Ease of manufacture
If single isomer esters are produced, then the manufacturing process is straightforward, but the resulting plasticizers have insufficient miscibility and application performance
Solution Approach 1:
The patent merges multiple isomeric nonanoic acids into a mixed ester product through a single esterification process with isosorbide. This approach maintains manufacturing straightforwardness (no need for separate purification of individual isomers) while achieving superior miscibility and application performance through the synergistic effect of the isomer mixture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The diester mixtures provide enhanced performance as plasticizers for PVC, ensuring better miscibility, low-temperature properties, and reduced viscosity, while being partially based on renewable resources, thus addressing sustainability and health risks associated with traditional plasticizers.
Implementation Method 1
the reaction can be carried out with branched or unbranched acids... in the presence of a macroporous, acidic ion exchange resin
Data Source
Figure 1
AI summary
The present invention relates to a mixture comprising diesters of the formula (I) where R1 to R8 = H or alkyl group having from 1 to 6 carbon atoms, where the R1 to R8 radicals may be the same or different, which is characterized in that at least two different diesters I are present in the mixture, said diesters differing in the structure of at least one of the carboxylic acid radicals C8H17COO present, to a process for preparing diesters of an isosorbide derivative of the formula I, in which a hexahydric alcohol and/or a monoanhydro or dianhydro derivative of the alcohol is esterified with a mixture of at least two different carboxylic acids of the empirical formula C8H17COOH, and to the use of these mixtures in paints, inks or coatings, in plastisols, adhesives or adhesive components, in sealants, as plasticizers in polymers or polymer components, as solvents, as lubricant oil components and as assistants in metal processing, and also PVC compositions or plastisols comprising PVC and from 5 to 250 parts by mass of the mixture per 100 parts by mass of PVC.