JPS5959438A - Manufacture of composite barriering film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a composite barrier membrane, and more particularly to a method for producing a composite barrier membrane having a specific surface protective layer and having excellent weather resistance.

As membrane materials for balloons, air membrane structures, etc., there is a desire for membrane materials that have barrier properties and are excellent in mechanical strength and weather resistance. Conventionally, for this purpose, composite barrier membranes have been proposed in which a reinforcing fiber layer is provided on one side of the barrier material to improve mechanical strength, and a surface protective layer is provided on the other side to provide weather resistance. . The surface protective layer has mainly been formed by laminating a polyvinyl fluoride film onto a barrier material via an adhesive layer.

However, in the conventional method for manufacturing composite membranes, the process is complicated and the weight of the resulting composite membrane is large because it is essential to interpose an adhesive layer between the surface protective layer/barrier layer. Not only does it have the drawback of not being used as a commercial product, but it is still insufficient in terms of weather resistance, and furthermore, it is difficult to repair defective parts or joints.

The present inventors have been aware of the above-mentioned problems, and as a result of intensive research, the above-mentioned surface protective layer is formed by forming a cured coating film using a specific method using a specific fluorine-containing copolymer. It has been discovered that such problems have been solved and a composite barrier membrane with excellent weather resistance can be produced smoothly.

The present invention has thus been completed based on the above findings, and provides a method for producing a composite barrier membrane having a surface protective layer, a single barrier layer and a reinforcing fiber layer, the main components being units based on tetrafluoroethylene and alkyl vinyl ether. Further, a coating composition prepared by adding a curing agent to an organic solvent solution of a fluorine-containing copolymer containing a monomer based on a monomer that strengthens reaction sites in a proportion of 20 molar or less is added to the barrier 4. A composite barrier characterized in that it is coated on one layer of the barrier layer of a laminate formed by laminating a reinforcing fiber layer and a reinforcing fiber layer, and a surface film-retaining layer is formed by volatilizing the solvent and curing the coating film. The present invention provides a new method for producing a group of compounds.

In the present invention, it is possible to use a fluorine-containing copolymer containing units based on tetrafluoroethylene and alkyl vinyl ether as main components and further containing units based on a monomer that strengthens the reaction site in a proportion of 20 mol or less. is important.

Here, the content ratio of tetrafluoroethylene and alkyl vinyl ether component units in the fluorine-containing copolymer is 70:30 to 3 from the viewpoint of weather resistance, flexibility, etc.
From the viewpoint of copolymerization properties and coating film properties, preferred alkyl vinyl ether components include straight button-like alkyl vinyl ether components having about 2 to 8 carbon atoms,
Examples include those containing a branched or cyclic alkyl group. As a comonomer that provides a reactive site in such a copolymer, functional group-containing vinyl ethers such as hydroxyalkyl vinyl ether or glycidyl vinyl ether can be preferably employed from the viewpoint of copolymerization properties. The content of units based on comonomers that provide reactive sites in the copolymer is 20 mol or less, preferably 1 to 15
It is about the size of morchi. If the polymerization ratio is too small, curing will be insufficient, and if the ratio is too large, the flexibility of the coating film will be impaired, both of which are disadvantageous.

Copolymers such as those mentioned above are produced by causing a copolymerization reaction by allowing a polymerization initiator or a polymerization initiation source such as ionizing radiation to act on a monomer mixture in a predetermined proportion in the presence or absence of a polymerization medium. It can be manufactured by performing the following steps.

As the curing agent to be included in the coating composition in the present invention, curing aids such as various polyfunctional compounds having reactivity with the reaction sites of the fluorine-containing copolymer can be used. Alternatively, it can also be used in combination with a curing catalyst.

Although the curing agent is not particularly limited, it is usually copolymer 100
．． It is suitably selected from the range of about 0.1 to 100N-31 parts per part i, particularly about 0.5 to 50 parts by weight.

The type of curing agent is preferably selected appropriately depending on the type of the reaction site and the curing method.

For example, for a fluorine-containing polymer whose reactive site is a hydroxyl group, polyisocyanate or titanium alkoxide can be preferably employed as a curing agent when the composition is to be cured at room temperature. In addition, when the composition is of a heat-curing type, melamine curing agents, urea resin curing agents, polybasic acid curing agents, etc., which are used in ordinary thermosetting acrylic paints, are effective as curing agents. Here, examples of the melamine curing agent include butylated melamine, methylated melamine, epoxy-modified melamine, etc.
-B with various degrees of modification can be used, and the degree of self-condensation can be selected as appropriate. Examples of the urea resin include methylated urea, butylated urea, and the like. Further, as the polybasic acid curing agent, long-chain aliphatic dicarboxylic acids, aromatic polycarboxylic acids or their anhydrides, block polyvalent incyanates, and the like are useful. When using melamine or urea hardeners, curing can be accelerated by adding an acidic catalyst. As another example, when the reactive site of the fluorine-containing polymer is an epoxy group, amines, carboxylic acids, phenols, alcohols, etc. are effective as curing agents. Aromatic diols are useful as curing aids.

In the present invention, the coating composition includes an ultraviolet absorber,
By adding various components such as colorants and water repellency imparting components, it is also possible to improve various properties of the film, such as durability, aesthetics, and water repellency.

The coating composition can be applied by various methods including, but not limited to, brush coating, dip coating, roll coating, flow coating, and spray coating, but from the viewpoint of productivity and uniformity of the coating film, etc. , spray painting and roll coating methods can be preferably employed.

In the present invention, the type of organic solvent, the volatilization of the solvent, and the conditions for curing the coating film are not particularly limited, and are desirably selected depending on the purpose of the composite film and the curing method. From the perspective of the relationship between curing conditions and type of solvent, room temperature curing or 8
For low temperature curing down to about 0'C, xylene, toluene, ethyl acetate, butyl acetate, methyl ethyl ketone,
Solvents mainly consisting of low boiling point solvents such as methyl isobutyl ketone and butanol are used, and in the case of baking at high temperatures such as 120 to 140°C, high boiling point solvents such as high boiling point aromatic solvents and cellosolve acetate are used. Those added appropriately to a low boiling point can be preferably employed.

The thickness of the cured coating Mff< formed by hiding is as follows.
Usually, the range is 5 to 60 μm, preferably 10 to 60 μm. If it is too thin, the effectiveness of the R&D association will decrease,
Moreover, if it is too thick, it is not an uneconomical υ, but a 9-strain part that is unsuitable for applications where lightness is required.

In the present invention, various materials can be used as the barrier agent, including those conventionally known or well known, such as films made of polyethylene terephthalate, saponified ethylene-vinyl acetate copolymer, aromatic polyamide, and even polyacrylonitrile. Illustrated. Further, the reinforcing fiber phase is similarly not limited to polynisder fibers, aromatic polyamide fibers, etc., and various materials can be employed.

In this paper, the difference between barrier material and reinforcing fiber material is 1.
It is important to form a cured coating as described above on the barrier layer of the layer. By forming the surface protective layer in this manner, various advantages are exhibited, especially when the film is put to practical use.

In other words, it is possible to form a surface pupil retaining layer after forming a laminate of a barrier layer and a reinforcing fiber phase into a practical shape, which is relatively easy to bond, increasing the degree of freedom in the shape of length products. Along with this, workability has been greatly improved, and joints and defective parts can be repaired easily and completely.

According to the present invention, it is possible to easily manufacture a composite barrier film that has high gas barrier properties, high mechanical strength, and excellent weather resistance, and has particular utility in the field of film materials for outdoor use. is extremely large.

The present invention 2 will now be described in more detail with reference to Examples.

Example 1 The following coating composition was prepared using fluorine-containing copolymers containing units based on detrafluoroethylene, ethyl vinyl ether, and hydroxybutyl vinyl ether in proportions of 50 molti, 35 molti, and 15 molti, respectively. was prepared.

Fluorine-containing copolymer 100v parts Isocyanate curing agent (manufactured by Sumitomo Bayer Urethane: Teith Module N) 15
' dibutyltin dilauryl) 0.00
03"Titanium oxide (manufactured by 6 Hara Sangyo: 0R-90)
40' mixed solvent 200'
However, the mixed solvent is methyl isobutyl ketone, xylene, ethyl acetate, and cellosolve acetate in a weight ratio of 1 +
They were mixed at a ratio of 1:i:0.5.

The coating composition obtained above was spray-coated onto the barrier layer of the laminate having the following structure so that the dry film thickness was 20 μIn, and the coating was left at room temperature for 7 days to cure the coating film. A composite barrier membrane was obtained.

Barrier layer: polyethylene terephthalate biaxially stretched film (12 μm) Adhesive layer: urethane thread (60 μm) Reinforcing fiber layer, polyethylene terephthalate tire cord plain woven fabric (1355′/m 2 ) The thus obtained composite barrier film was When subjected to a 400-hour accelerated weathering test using a U-cycle weather meter, it was confirmed that almost no deterioration occurred as shown below.

Before test After test [Barrier material/reinforcing fiber material] Adhesive strength 1.4
t4 (K9/crn) Helium permeability (cc/l, 'l-1-24hr-at
410 380 Repeated bending resistance (crack occurrence)
)20)20 On the other hand, in the case of a laminate body without the above-mentioned surface layer, when an accelerated weathering test using a similar due cycle weather meter was conducted, the barrier deterioration was significantly deteriorated, and the adhesive strength and helium permeability were significantly deteriorated. Neither measurement was included^], and shrift occurred due to one bending.

Example 2 Units based on tetrafluoroethylene, cyclohexyl vinyl ether, imbutyl vinyl ether and hydroxyphthyl vinyl ether are prepared! 50 morti each,
The following coating compositions were prepared using fluorine-containing copolymers containing 25 moles, 15 moles, and 10 moles.

Fluorine-containing co-assembly 100 parts by weight titanium oxide (Ishikata Sangyo: 0R-90) 40" Mixed bath additive 200" Melamine resin (Mitsui Toatsu: Cymel 325) 10" Curing catalyst (Catalys 6000) 0.5' UV absorber 10' (Kyodo Yakuhin: Vi
osorb-130) The mixed solvent includes xylene, butanol, ethylcerone, and high-boiling aromatic solvent (
Manufactured by Tonen: Solbetsu Sona 150) i-weight ratio 1:1; 1
:3 ratio.

The above coating composition was applied onto the same laminate as in Example 1 using a roll coater so as to have a dry smoke film thickness of 20 pm K, and was hardened at 120° C. for 40 minutes.

Thus, I41 et al! After a 400-hour forced Itlf test using a due cycle weather meter, the adhesive strength of the composite barrier membrane (barrier material/reinforcing fiber material) was 1.4 K or 7 m.

Claims (1)

[Claims] (1) A method for producing a composite barrier film having a surface pupil retention layer, a barrier layer and a reinforcing fiber layer, in which the main component is a unit based on tetrafluoroethylene and an alkyl vinyl ether, and further contains 20 units based on a monomer providing a reaction site. On the barrier layer of a laminate formed by laminating a barrier material and a reinforcing fiber material, a coating composition comprising a hardening agent TA in an organic solvent solution of a fluorine-containing copolymer containing a proportion of less than 10% 1. A method for producing a composite barrier film, the method comprising forming a surface protective layer by coating the film on the surface of the film, volatilizing the solvent, and curing the film.