JPH041776B2 - - Google Patents

Description

[Detailed description of the invention]

In the present invention, after subjecting a polymer sheet to low-temperature plasma treatment, a monomer and/or polymer dispersion of one or more radically polymerizable fluorine-containing compounds and/or silane compounds and a transition metal salt dispersion are added. The present invention relates to a method for processing a sheet material, which is characterized by forming an apparent graft polymerized layer having durable water repellency by exposing the material to water and heating it. Conventionally, durable water-repellent finishing methods for polymer sheet-like materials, such as paper, films, non-woven fabrics, and woven and knitted fabrics, involve applying a water-repellent agent of a fluorine-containing compound and/or a silane compound to the sheet-like material, followed by heat treatment. The method was to do so. However, all water repellent finishing methods using heat treatment methods have the drawback of lacking washing durability. The cause is that the water repellent agent falls off due to repeated washing. Therefore, in order to improve durability, polymer sheet materials are pretreated and then treated with water repellent treatment, or treated with a combination of water repellent agent and crosslinking agent. At present, water-based products are not available. The present inventors aimed to develop a durable water-repellent finishing method that does not have the above-mentioned drawbacks, and as a result of their extensive efforts, they have arrived at the present invention. The polymer sheet material as used in the present invention is paper, film, nonwoven fabric, woven or knitted fabric made of natural polymers, synthetic polymers, or the like. In the present invention, low-temperature plasma treatment on at least one side means that if plasma treatment is applied to only one side of a sheet-like material, active points capable of radical polymerization will be formed on only one side, and the subsequent graft polymerization reaction will make only one side durable and water repellent. It is possible to form an apparent graft-polymerized layer with a durable water-repellent property on both sides, and if both sides of the sheet-like material are treated and reacted, it is possible to form an apparent graft-polymerized layer with durable water repellency on both sides. It means that. The low-temperature plasma treatment referred to in the present invention is a gas discharge different from arc discharge or corona discharge, and the ion species constituting the plasma include Ar, He, H ₂ ,
Plasma is generated using a gas such as N ₂ , NO ₂ , O ₂ , Air, fluorocarbon, halogenated carbon, hydrocarbon, or a mixture thereof using a direct current, alternating current, or high-frequency power source. In this case, it is preferable to generate plasma between electrodes with an inter-electrode spacing of 1 cm or more and 10 cm or less using an AC high-frequency power source in a gas atmosphere under vacuum. However, if the degree of vacuum is high, the distance between the electrodes should be If the degree of vacuum is low, it is better to narrow the distance between the electrodes. Both electrodes may be a pair of plate-shaped or rod-shaped electrodes, or a combination of a rod-shaped electrode and a drum-shaped or plate-shaped electrode, respectively. moreover,
The electrode surface may be coated with glass, ceramics, or the like. Further, the electrode may be cooled or heated as necessary. Low-temperature plasma processing equipment may use either an electrode with one electrode grounded to the can or an ungrounded electrode with both electrodes insulated from the can; however, it is not recommended to use an ungrounded electrode. For example, it has the advantage of being able to perform the same processing with about half the power of a grounded type. By fixing or moving the polymer sheet in contact with or floating on a drum-type or plate-shaped electrode, uniform active points capable of radical polymerization can be generated. It is possible to obtain a sheet-like product having The low-temperature plasma processing conditions related to the present invention can be determined by the gas pressure and processing electrical energy during discharge. The gas pressure in low temperature plasma treatment is 0.01
It is necessary that the temperature is not less than mmHg and not more than 20mmHg.
That is, practical use at 0.01 mmHg or less is not preferable because it requires a precise device. At 20 mmHg or more, the discharge becomes unstable, causing localized discharge, which tends to damage the base material, and makes it difficult to generate active points. The gas pressure of the present invention is preferably 0.05mm
The range is Hg or more and 10mmHg or less. More preferably, it is 0.1 mmHg or more and 0.2 mmHg or less. It has been found that within this range, the largest number of radically polymerizable active sites is generated within the range that the present inventors have diligently investigated without damaging the sheet-like material. That is, when a high amount of graft polymer is required.
Plasma treatment at 0.1 mmHg or more and 0.2 mmHg or less is an effective method. Usually 0.05mmHg
A range of 10 mmHg or more is sufficient. The gas used in the low-temperature plasma treatment in the present invention is a gas that does not contain oxygen and can form active sites capable of radical polymerization, or a gas that contains oxygen gas. In the present invention, gases that do not contain oxygen and can form radically polymerizable active sites include Ar, He,
These gases include H ₂ , N ₂ , NO ₂ , NO, CO ₂ , CO, halogen, halogenated carbon, fluorinated carbon, hydrocarbon, etc., or a mixture of these gases. Next, typical gases containing oxygen gas include oxygen and air. The oxygen-containing gas is not particularly limited, and a mixture of the above gases may be used. The processing electric energy in low-temperature plasma processing is 1 watts/cm ² or more and 2000 watts/cm ²
It is necessary that the following is true. The processing electric energy can be expressed as E=W×T/S (watts/seconds/cm ² )W; discharge output (watts) T; processing time (seconds) S; electrode area (cm ² ). When the processing electrical energy is less than 1 watt/sec/ ^cm2 , the
Example 80443 describes that a relatively high amount of graft polymer can be obtained, and that the amount of graft polymer can be freely controlled within this range by changing the plasma treatment time. Indeed, such a tendency was confirmed below 1 Watt·sec/cm ² .
However, as a method for freely controlling the amount of graft polymer, the adjustment range of plasma treatment time is too narrow, and detailed control is actually difficult. Furthermore, if the electrical energy for the process is 2000 watts/sec/cm ² or more, there is a risk of damage to the can body and the base material, which is not suitable for practical use. In the present invention, the particularly preferable processing electrical energy is 5 watts/cm 2 or more and 1000 watts/cm ² or more.
^cm2 or less. In particular, for the treatment of sheet materials used in normal graft polymerization, it is necessary to perform plasma treatment with a stable amount of active points that can be radically polymerized in the range of 5 watts/cm ² to 50 watts/cm ² . This is preferable from the viewpoint of practical use and production control. However, the apparent amount of graft polymer can be controlled by
This is possible depending on the transition metal salt used in combination with the monomer and the graft polymerization reaction conditions. Further, if a high apparent amount of graft polymer is required, it is possible to appropriately select a processing electric energy from 50 watts/cm ² to 2000 watts/cm ² . The generation of low-temperature plasma occurs between the counter-discharge electrodes under the gas pressure and processing electrical energy, at a frequency of 5KHz to
High frequencies such as 100MHz can be used.
Furthermore, as the discharge frequency band, in addition to the above-mentioned high frequency, low frequency, microwave, direct current, etc. can also be used. The low-temperature plasma generator may be of a capacitive coupling type, such as an external electrode type or a coil type, or an inductive coupling type. The sheet-like material whose surface has been treated with low-temperature plasma is then exposed to oxygen gas or a mixed gas containing oxygen gas, or taken out into the atmosphere, and the radically polymerizable material generated on the surface of the sheet-like material by the plasma treatment is exposed to oxygen gas or a mixed gas containing oxygen gas. React active sites with oxygen. It is not necessary to perform this operation if plasma treatment is performed in oxygen gas or a mixed gas containing oxygen gas. The amount of radically polymerizable active sites produced on the surface of the sheet-like material treated in this way is 10 ^-11 mol/cm ² or more and 10 ^-8 mol/cm ² or less. When the amount of active sites produced is 10 ^-11 mol/cm ² or less, the apparent amount of graft polymer is small. In addition, according to detailed experimental studies by the present inventors, the amount of active sites generated is 10 ^-8 mol/
A large amount of energy is required to increase the temperature to cm ² or more, and the cost becomes too high for practical use. In particular, the preferred amount of active sites for graft polymerization is 10 ^-10 mol/
^cm2 or more and ^10-8 mol/ ^cm2 or less. The thus treated sheet material is then treated with a monomer and/or polymer dispersion of 0.1% or more and 100% or more of one or more radically polymerizable fluorine-containing compounds and/or silane compounds. ,
Bring it into contact with a transition metal salt dispersion of 0.0001% or more and 1% or less. When the sheet material is brought into contact with the monomer and/or polymer dispersion and the transition metal salt dispersion, the combination and order are not particularly determined. The method of bringing the sheet material into contact with each dispersion liquid is not particularly defined, such as dipping dip coating. The point is that it is sufficient to touch the surface of the sheet material that has active sites capable of radical polymerization. Furthermore, an inert gas and/or superheated steam may be introduced into the dispersion before or after the sheet material comes into contact with the monomer and/or polymer dispersion and the transition metal salt dispersion, or during the reaction. The graft polymerization reaction is promoted by removing oxygen. When bringing the sheet material having active sites capable of radical polymerization into contact with the monomer and/or polymer dispersion liquid or the transition metal salt dispersion liquid, the surface of the sheet material is heated to a temperature of 0.1 mmHg or higher in advance.
The graft polymerization reaction proceeds more easily by removing oxygen gas, impurities, etc. contained in the sheet-like material by vacuum degassing at 100 mmHg or less or blowing with high-pressure inert gas. There is also nothing wrong with carrying out vacuum deaeration or the like after contacting with the monomer, etc. The concentration of the monomer and/or polymer dispersion is
0.1% or more and 100% or less. Preferably it is 0.1% or more and 50% or less. Within this range, by using the transition metal salt, it is easy to suppress the homopolymerization reaction and increase or control the apparent amount of graft polymer. The concentration of the transition metal salt dispersion is 0.0001% or more, 1
% or less. If it is less than 0.0001%, the effect of suppressing the homopolymerization reaction is extremely low and is not of practical use. Furthermore, if the content is 1% or more, the sheet-like material will be significantly colored, making it impractical. Further, by changing the transition metal salt concentration by changing the monomer concentration, reaction temperature, and reaction time, it is possible to increase or control the apparent amount of graft polymer. The reaction temperature is preferably room temperature or 20°C or more and 80°C or less. The optimum temperature should be appropriately selected depending on the reactivity of the monomer, monomer concentration, transition metal salt concentration, and reaction time, and is not particularly limited. The reaction time is in the range of 10 seconds or more and 10 hours or less. The reaction time should be selected depending on the reaction method, reaction temperature, monomer and/or polymer concentration, transition metal salt concentration, etc., and is not particularly limited. The graft polymerization reaction method includes a method in which the sheet material is brought into contact with a mixed solution of a monomer and/or polymer and a transition metal salt and heated at the same time;
After contacting the mixed solution, the sheet material is appropriately squeezed and heated, or furthermore, the sheet-like material is heat-treated in a reaction apparatus and then immediately brought into contact with the mixed solution and heated in the same bath or separately. You can do it. Furthermore, as described above, there is no problem in carrying out the graft polymerization reaction by bringing the monomer and/or polymer and the transition metal salt into contact with the sheet material separately. It is preferable to exclude oxygen from inside the graft polymerization reaction apparatus. Dissolved oxygen in the dispersion liquid can be replaced with nitrogen gas, other inert gas, or superheated steam, or in the case of a solution, the solvent can be degassed by boiling in advance, or the sheet material and the monomer and/or heavy After coalescence and contact with the transition metal salt, it is preferable to squeeze the mixture with a mangle and introduce it into superheated steam to remove as much oxygen as possible. Even if the monomer and/or polymer dispersion consists of an aqueous medium containing a wastewater-soluble monomer and/or polymer and an emulsifier, there is no problem in the graft polymerization reaction. In particular, fluorine-containing compounds and silane compounds are insoluble in water, so either an organic solvent or the emulsification system described above must be used. Each has its advantages and disadvantages and cannot be particularly limited. In addition, on the surface and inside of the sheet-like material, inorganic fine particles that do not inhibit radical polymerization, such as SiO ₂ ,
There is no problem with the presence of Al ₂ O ₃ and there is no problem with the presence of Al 2 O 3 in the monomer and/or polymer dispersion. The radically polymerizable monomer and/or polymer used in the present invention should be selected depending on the appropriate use and is not particularly limited. The monomer of the radically polymerizable fluorine-containing compound is a compound having a carbon-carbon double bond,
It is a monomer that polymerizes using radicals as propagating terminals. Examples include fluoroethylene compounds, fluorovinyl compounds, methacrylic or acrylic compounds having a fluoroalkyl group, styrene compounds, and acrylamide compounds. Monomers of radically polymerizable silane compounds are those having at least one carbon-carbon double bond and at least one Si atom in the molecule, or those having Si-x (x is a halogen) in the molecule. )
Refers to a silicon-containing organic compound that has a bond. Examples include halogenated silicon, halogenated alkylsilane, alkoxysilane and/or methacrylic having an alkylsilane group, acrylic compound, vinyl compound, styrene compound, acrylamide compound, and the like. A radically polymerizable polymer of a fluorine-containing compound and/or a silane compound is a homopolymer of the above monomer or a copolymer with a monomer other than the above, and there is no unreacted carbon in the polymer mixture. -carbon double bonds and
It is characterized by the remaining Si-x bonds. The transition metal salts used in the present invention include FeCl ₂ ,
( _NH4 ) _2Fe ( _SO4 ) ₂ , CuCl, Cu( _NO3 ) ₂ , _CuSO4 ,
CuCl ₂ , Ni(NO ₃ ) ₂ , Co(NO ₃ ) ₂ , Cr(NO ₃ ) ₂ , Pb
Examples include (NO ₃ ) ₂ and LiCl. The sheet-like material,
Depending on the monomer, polymer, reaction conditions, etc., it is possible to select one that suits the purpose. The graft polymerization reaction product of the monomer formed on the surface of the sheet material includes a graft polymer, a homopolymer with good durability, a homopolymer with poor durability,
Contains unreacted monomers, etc. The graft polymerization reaction product is washed in a good solvent of the monomer and the polymer at a temperature of 35°C to 65°C lower than the boiling point of the good solvent, or is subjected to ultrasonic cleaning. or, in the absence of a suitable good solvent, by ultrasonic washing for 1 hour in water or a good monomer solvent to remove unreacted monomers and poorly durable homopolymers. , an apparent graft polymerization layer. That is, the apparent graft polymer layer is composed of an apparent graft polymer containing a graft polymer and a homopolymer having good durability. Furthermore, by washing the apparent graft polymer layer with a good solvent for the polymer at a temperature of 0°C to 25°C lower than the boiling point of the solvent or by ultrasonic cleaning, or when there is no suitable good solvent. A homopolymer having good durability is also removed by ultrasonic cleaning for 5 hours in water or a good solvent for the monomer, and the resultant layer is used as a graft polymerization layer. The graft polymer layer is made of a graft polymer. After the graft polymerization reaction, the homopolymer having poor durability and unreacted monomers in the graft polymerization reaction product of the monomers formed on the surface of the sheet material are removed by chemical or physical methods. By carrying out , it is possible to obtain a graft polymerized layer that appears to have good durability. Chemical and physical methods include water washing, solvent extraction, ultrasonic cleaning, etc. By this step and the polymerization reaction conditions, it is possible to control the homopolymer content with good durability in the apparent graft polymerization layer of the monomer. By containing 90% or less of a homopolymer with good durability in the apparent graft polymerization layer, it is possible to form a polymerization layer suitable for various purposes. The present invention is different from conventional water-repellent finishing methods, and is a method of forming an extremely durable water-repellent layer that is chemically bonded to a polymer sheet by performing graft polymerization. The present invention will be explained below with reference to Examples. Example 1 One side of a polyester processed yarn fabric was subjected to low-temperature plasma treatment for 20 seconds using an internal electrode type plasma device at a frequency of 13.56 MHz, an output of 1.24 W/sec, and a degree of vacuum of 0.15 mmHg, introducing Ar gas for 20 seconds. Formed active sites that can be polymerized. Subsequently, after being taken out into the air, the degree of vacuum was reduced in a graft polymerization reaction tank.
After vacuum degassing at 10 mmHg for 30 seconds, the surface with 3.5 × 10 ^-10 mol/cm ² of active sites capable of radical polymerization was
After heating to 80°C on a hot plate, immediately dip nip it into a reaction dispersion having the composition shown in Table 1 at room temperature, and immediately bring it to 80°C while the pick-up is 100%.
After being exposed to heated N ₂ for 20 minutes, it was ultrasonically cleaned in acetone at 20°C for 1 hour.

[Table] The water-repellent sheet material showed a water repellency of 100 points according to the shower method, and after 50 home washings, the water repellency was 90 points.
It showed good durability and water repellency. Oil repellency is
It showed 100 points, and after 50 home washings, it showed 90 points, indicating that it was sufficiently effective. Example 2 Both sides of a nylon taffeta were subjected to low-temperature plasma treatment for 30 seconds in air at a frequency of 110 KHz, an output of 2.55 W/sec, and a degree of vacuum of 0.20 mmHg using a non-grounded electrode insulated from the can body. While the sheet-like material was immersed in the reaction dispersion shown in Table 2, it was vacuum degassed and N ₂
After repeating the introduction and sufficiently deaerating the inside of the reaction tank, it was heated to 60°C and left for 1 hour. This was followed by ultrasonic cleaning in acetone at 20°C for 1 hour.

[Table] This processed sheet material showed water repellency of 100 points, and even after 50 home washings, it showed water repellency of 90 points and had good durability. Example 3 Both sides of cotton fabric were heated at a frequency of 110 KHz and an output of 1.24
Low-temperature plasma treatment was performed for 30 seconds in O ₂ gas at watts per second and a vacuum level of 0.1 mmHg using a non-grounded electrode insulated with respect to the can body. Dip-nip the sheet into the reaction dispersion shown in Table 3 and pick it up.
At 90%, it was immediately placed in superheated steam for 20 minutes. The water-repellent layer on the processed sheet material obtained in this way is
This was used as a graft polymerization reaction product.

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Claims (1)

[Claims] 1. At least one side of the polymer sheet-like material is
Under a gas pressure of mmHg or more and 20 mmHg or less that does not contain oxygen gas and can form active sites capable of radical polymerization,
After low-temperature plasma treatment with electrical energy of 1 watt-second/ ^cm2 or more and 2000 watt-seconds/ ^cm2 or less,
Exposure to oxygen gas or a mixed gas containing oxygen gas, or 0.01 mmHg or more in advance
Under gas pressure containing oxygen gas of 20 mmHg or less, electrical energy of 1 watt sec/cm ² or more 2000 watts.
By subjecting the sheet-like material to a low-temperature plasma treatment at a rate of 10 ^-11 mol/cm ² or ^more and 10 ^-8 mol/cm ² or less, which is capable of radical polymerization, by subjecting it to low temperature plasma treatment at a rate of 0.1% or more and 100 mol/cm 2 or less. % or less of a monomer and/or polymer dispersion of one or more radically polymerizable fluorine-containing compounds and/or silane compounds;
Before or after contact with a transition metal salt dispersion of 0.0001% or more and 1% or less, or during the reaction, inert gas and/or superheated steam is introduced into the dispersion to remove oxygen, at room temperature or by heating. A durable water repellent finishing method characterized by forming an apparent graft polymerized layer of the monomer on the surface of the sheet-like article. 2 The apparent graft polymerization layer of the monomer is 90%
The durable water repellent finishing method according to claim 1, which comprises the following homopolymer with good durability. 3 Radically polymerizable fluorine-containing compound and/or
The durable water repellent finishing method according to claim 1, wherein the monomer and/or polymer dispersion of the silane compound comprises an aqueous medium containing an emulsifier. 4. Durability according to claim 1, characterized in that the surface of the sheet-like material on which active sites capable of radical polymerization are formed is deoxidized by vacuum degassing or blowing with high-pressure inert gas. Water repellent processing method. 5. A method comprising the step of removing homopolymers with poor durability and unreacted monomers from the graft polymerization reaction product of the monomers formed on the surface of the sheet-like article by chemical and physical methods. A durable water repellent finishing method according to claim 1. 6. The durable water-repellent finishing method according to claim 1, wherein the low-temperature plasma treatment is performed on the can body using an insulated, non-grounded electrode.