医療用途向け短鎖撥水／撥油剤アサヒガードの開発

Res. Reports Asahi Glass Co., Ltd., 64（2014）
医療用途向け短鎖撥水／撥油剤アサヒガードの開発
Novel Fluorinated Water/Oil Repellent Agent（Rf-WOR）
with Short Carbon Chain for Medical Non-woven
増田祥*・井上広章**・山根伸***・杉山和典****
Sho Masuda, Hiroaki Inoue, Shin Yamane and Kazunori Sugiyama
要旨
医療用不織布は手術着を始めとする使い捨ての医療布帛に使用されており、比較的安定した成長
が見込める市場である。40年超の歴史を持つ撥水撥油剤AsahiGuardも古くから本市場で使用され
てきたが、Stewardship programへの同意により、従来のCmRf*1系製品からの切り替えが必要と
なりC6Rf*2系製品を開発するに至った。ポリマー設計のポイントとして、基材の表面抵抗値制御と
基材浸透性目的で加工時併用されるイオン性添加剤との混和安定性を重視して検討を進めた結果、
短鎖炭化水素アルキルアクリレートと両性イオン界面活性剤が採用された。
Summary
Medical Non-woven is used for disposable medical fabric such as surgical gowns. This
market is expected to have continuous growth.
AsahiGuard: water-based polymer type ﬂuorinated water/oil repellent（Rf-WOR）agent is
applied for this application for long time. However, it was necessary to convert to short
chain-type Rf from CmRf*1 product following US-EPA Stewardship program. Therefore, the
short chain-type C6Rf *2 -WOR agent for specifically non-woven medical textiles was
developed. Acrylate with short hydro-carbon chain and amphoteric surfactant were adopted
considering the surface resistibility and the compatibility to variable ionic ingredients, for
example antistatic agent, as a key point of polymer design.
*1 CmRf: the mixture of perfluoroalkyl（Rf）chain having more than 8 carbons
*2 C6Rf: perﬂuoroalkyl（Rf）chain having 6 carbons
*化学品カンパニー事業統括本部技術グループAGC Chemicals Business Management General Div. Material Technology Group
**化学品カンパニー技術統括本部開発部AGC Chemicals Technology Management General Div. Research & Development Div.
***モノづくり人づくり推進室AGC MONOZUKURI & Personal Growth Enhancement Oﬃce
****化学品カンパニー事業統括本部技術グループAGC Chemicals Business Management General Div. Material Technology Group
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旭硝子研究報告 64（2014）
Table 2. Test method for medical non-woven
Introduction
A m e d i c a l n o n - w o v e n i s w i d e l y u s e d f o r
disposable medical uniforms including surgical
gown, and its market is expected to have
continuous growth. AsahiGuard: water based
fluorinated water/oil repellent（Rf-WOR）agent
which is acrylic co-polymer emulsion is applied for
this usage for long time.
However, in January 2006, the EPA approached
manufacturers of ﬂuorinated resins and ﬂuorinated
water/oil repellent agents to participate in a
program to reduce emissions of perﬂuorooctanoic
acid（PFOA）
, longer chain length-perfluoroalkyl
carboxylic acids（PFCAs）and their precursors.
T h e n , w e d e d i c a t e d t o d e v e l o p t h e n e x t
generation type WOR with short alkyl chain（C6）
agent, meeting the goal of being free of them.
*3 AATCC: American Association of Textile Chemists and
Colorists
1. Classiﬁcation of non-woven
Non-woven is classified by structuring process
and bonding method of web. The web is
entanglement of ﬁbers. Table 1 shows the types of
non-woven. Many kinds of materials are used for
non-woven, for example, natural fibers, synthetic
polymers, metals, ceramics and pulps. As for
medical use, spunlace in wet process and
spunbond are commonly used. Especially, PP-SMS
（Polypropylene Spunbond/Melt blown/Spunbond）
is the most popular for it, because of high strength
and high water repellency.
Table 1. Type of non-woven
2. Speciﬁcations for medical
non-woven
World Strategic Partners（WSP）such as INDA
in USA and EDANA in EU makes specifications
for medical non-woven. Therefore, each non-woven
producers are required to accept and fix the
target properties based on WSP standard. WSP
speciﬁcations are listed in Table 2.
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There re two processes for giving the repellency
to non-woven with WOR agent, one is melt
additive type and the other is ﬁnishing type. Nonwoven is made of master batched polypropylene
including WOR agent in the melt additive type.
On the other hand, the treatment with WOR agent
is done after non-woven production in the ﬁnishing
type.
In the case of medical application, WOR agent is
required to give the alcohol repellency and the
antistatic property in order to avoid second
infection. Generally, the antistatic property is
given by antistatic agent co-mixed with WOR
agent. Furthermore, the water resistance keeping
with the original water repellency of raw fabric is
also required in the WOR agent. The coexisting of
these properties is an important point in the
related development, because the antistatic agent
is a kind of surfactant based on the hydrophilic
part and sometimes it makes the water repellency
decrease. The target properties of a customer are
summarized in Table 3.
Res. Reports Asahi Glass Co., Ltd., 64（2014）
（meth）
acrylate, which has a long aliphatic alkyl
chain, is a popular co-monomer and applicable for
this purpose. Such long aliphatic side-chain
segment also shows high resistibility, too. Then,
the relationship between the chain length of alkyl
acrylates and the surface resistibility was studied
and evaluated. The results are shows in Graph 1.
Table 3. Requirement for PP-SMS
Graph 1：Relationship between chain length of
alkyl acrylate co-monomer and surface resistibility
3. Polymer designing
Firstly, we evaluated the treatment of PP-SMS
fabric with conventional short chain WOR agent.
The results of the performance are listed in Table
4.
Table 4. Performance of short chain WOR for textile
Chain length of arkyl acrylate co-monomer
It is clearly shown that as the chain length of
alkyl acrylate is getting longer, the surface
resistibility is also increasing. In the relatively
short chain length region, the surface resistibility
achieves lower than 100 Giga ohm.
Preparation of sample
1）Main component of C6Rf type WOR for textile:
Copolymer of（meth）
acrylate with short chain Rf
（Rf: Carbon chain length=6）
2）Substrate: PP-SMS
3）Treatment Process: 1 dip-1 nip
2
（Squeezing pressure:4kgf/cm ）
4）WOR concentration in padding liquor:0.25% as solid
5）Curing condition: 125 degC for 4min
（not material temp.）
4. Design of Emulsion Ionicity
One of the major issues to solve is the reduction
of the surface resistibility. As describe above, the
surface resistibility can be reduced by antistatic
agent, which is mixed with WOR in its formulation.
Then, it is estimated that our customers choose
their own appropriate antistatic agents, since an
antistatic agent is a kind of ionic surfactant. When
the water-based WOR agent and the antistatic
agent have opposite ionic charges in each others,
the formulation stability should become worse and
the sedimentation should be generated in padding
liquor. Additionally, this kind of ingredient would
raise formulation cost. Therefore, a differentiated
WOR agent with low surface resistibility compared
to competitors products would be strongly
required. Based on the above mentioned
motivation, we began to study on the reduction of
the surface resistibility.
Main component of Rf-WOR is a copolymerized
product consisted of Rf group containing（meth）
acrylate（Rf acrylate）and other co-monomers. Rf
acrylate shows high resistibility and is a
composition must-have from the point of
repellency. Alkyl（meth）
acrylate such as stearyl
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Generally, the ionicity of water based WOR
agents for textiles is designed to be cationic in
order to keep on aﬃnity to substrate. As described
above, ionic surfactants like antistatic agents are
applied to WOR formulation for medical nonwoven. Table 5 shows typical antistatic agents
with the iconicity and the structural formula. All
products listed in Table 5 are commercially
available.
Table 5：Typical antistatic agent
In order to give the compatibility with all kinds
of antistatic agents, WOR emulsion is designed as
charge neutrality Charge-neutral surfactant is
nonionic one. However, nonionic surfactant has
bigger molecular weight compared to anionic or
cationic ones due to long oxyalkylene chain. From
the point of permeability into fibers, ionic
surfactants could be better than nonionic, because
of higher mobility due to lower molecular weight.
旭硝子研究報告 64（2014）
Then, we paid attention to amphoteric surfactants
and evaluated them for the current research
study. Typical structure of amphoteric surfactant,
N ,N -dimethyl-N -alkyl-N -carboxymethylammonium
betaine, is shown in Figure 1.
5. Conclusion
I n c o n c l u s i o n , t h e a c r y l a t e w i t h s h o r t
hydrocarbon moiety as a co-monomer and the
chosen amphoteric surfactant were applied for
newly developed short chain（C6）
Rf-WOR agent
formulation. The（C6）
Rf-WOR system gives lower
than 100 G ohm of surface resistibility and shows
better compatibility with ionic ingredients, keeping
the appropriate repellency.
Fig. 1. Amphoteric surfactant
̶
Table 6 shows the result of formulation study
with amphoteric surfactant and cationic Rf-WOR
agent.
References ̶
不織布の基礎と応用：財団法人日本繊維機械学会（1993年8月）
Table 6. Result of formulation study for surfactant
Preparation of sample
1）WOR agent as a Control:
C6Rf acrylate/short chain alkyl acrylate/
Vinyl Chloride Monomer
Ionicity: cationic
2）Substrate: PP-SMS
3）Treatment Process: 1 dip-1 nip
2
（Nipping pressure:4 kgf/cm ）
4）WOR concentration in formulation: 0.25% as solid
5）Curing condition:125 degC for 4min
at atmospheric pressure
（not material temp.）
The above results clearly indicate that the
amphoteric surfactant can reduce the surface
resistibility without reduction of the required
repellency. After optimization of the monomer
components and the formulation for the adequate
accomplishment of the performance, we decided
the final product as a development work.
Measured values are listed in Table 7.
Table 7：Performance of ﬁnalized development product
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