TECHNICAL FIELD
Cross-reference to Related Applications
[0001] This application claims the benefit of Korean Patent
Application No. 10-2020-0124124, filed on September 24, 2020,
in the Korean Intellectual Property Office, the disclosure of
10 which is incorporated herein in its entirety by reference.
Technical Field
[0002] The present invention relates to a batch preparation
method of an ester-based material, the method configured to
15 control the pressure of a reactor in the batch-wise preparation
of the ester-based material.
BACKGROUND ART
[0003] Phthalate-based plasticizers had accounted for 92% of
the global plasticizer market by the 20th century (see
20 Mustafizur Rahman and Christopher S. Brazel, ”The plasticizer
market: an assessment of traditional plasticizers and research
trends to meet new challenges”, Progress in Polymer Science
2004, 29, 1223-1248), and are additives used for imparting
flexibility, durability, and cold resistance mainly to
25 polyvinyl chloride (hereinafter referred to as PVC) and
2
lowering the viscosity during melting to improve
processability. These phthalate-based plasticizers are added
in various amounts to PVC and widely used in various
applications from rigid products such as rigid pipes to soft
5 products which may be used for such as food packaging materials,
blood bags, flooring materials, etc. due to their soft and
good flexibility, and thus are more closely related to real
life than any other material, and the direct contact with the
human body may not avoidable.
10 [0004] However, despite the compatibility of the phthalatebased plasticizers with PVC and their excellent capability to
impart flexibility, it has been argued recently about
harmfulness of the PVC product containing the phthalate-based
plasticizers that the phthalate-based plasticizers may leak
15 out of the PVC product when used in real life, and act as a
presumed endocrine disrupting (environmental hormone)
substance and a carcinogen of the level of heavy metals (see
N. R. Janjua et al., “Systemic Uptake of Diethyl Phthalate,
Dibutyl Phthalate, and Butyl Paraben Following Whole-body
20 Topical Application and Reproductive and Thyroid Hormone
Levels in Humans”, Environmental Science and Technology 2008,
42, 7522-7527). Especially, since the report about the leakage
of di-(2-ethyl hexyl) phthalate (DEHP), which was the most
used phthalate-based plasticizer in the US in the 1960s, out
25 of the PVC product, the interest in environmental hormones has
3
been added in the 1990s and global environmental regulations
as well as extensive studies on hazards of the phthalate-based
plasticizers to human have started.
[0005] Therefore, in order to cope with environmental hormone
5 issues and environmental regulations due to the leakage of the
phthalate-based plasticizers, particularly di(2-ethylhexyl)
phthalate, a number of researchers have been conducting
research to develop a new, alternative, non-phthalate-based
plasticizer which is free of phthalic acid used in the
10 production of di(2-ethylhexyl) phthalate, a phthalate-based
plasticizer which is phthalate-based but free of the leakage
of plasticizers to be used for industrial purposes instead of
di(2-ethylhexyl) phthalate, or a leakage inhibition technology
which may inhibit the leakage of the phthalate-based
15 plasticizers to greatly reduce the hazards to human and be in
accordance with environmental standards.
[0006] Accordingly, as ester-based plasticizer.

CLAIMS
1. A method for preparing an ester-based material, the
method comprising:
5 a step in which in a batch reactor, under a catalyst, at
least one polycarboxylic acid selected from the group
consisting of a terephthalic acid, a phthalic acid, an
isophthalic acid, a cyclohexane dicarboxylic acid, a
cyclohexane tricarboxylic acid, a trimellitic acid, and citric
10 acid reacts with at least one mono-alcohol having 3 to 12 alkyl
carbon atoms,
wherein pressure in the reactor is configured such that
the pressure at the early stage is 0.3 barg to 1.0 barg and
the pressure at the latter stage is 0 barg to 0.5 barg, the
15 pressure at the early stage being greater than the pressure at
the latter stage, and
the early and latter stages are divided based on any one
of the time points when reaction conversion rate is 30% to 90%.
20 2. The method of claim 1, wherein the batch reactor has an
early stage pressure of 0.4 barg to 1.0 barg, and a latter
stage pressure of 0 barg to 0.4 barg.
3. The method of claim 1, wherein the mono-alcohol is added
25 in excess of 20 mol% to 100 mol% relative to polycarboxylic
42
acid equivalent.
4. The method of claim 1, wherein:
the reaction is performed in the presence of a catalyst;
5 and
the catalyst is added at one or more time points before
the initiation of the reaction and in the course of the
reaction.