JPH04351643A - Method for activating surface of low-activity high-molecular substance - Google Patents

Abstract

PURPOSE:To provide an excellent method suitable for activating the surface of a low-activity high-molecular substance before it is coated, printed, bonded, or dyed. CONSTITUTION:The surface of a low-activity high-molecular substance is brought into contact with a solvent and irradiated with ultraviolet rays having a wavelength of 2000Angstrom or lower. pref. the main working mavelength being 1849Angstrom . The solvent is prepd. by hydrogenating arom, rings of a kerosene fraction boiling at 150-300 deg.C, removing n-paraffins from the fraction with a molecular sieve made of a synthetic zeolite, and separating a fraction boiling at 150-300 deg.C and being substantially free from naphthalene or biphenyl from the resulting residual oil by rectification.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for activating the surface of a low-activity polymeric substance. For more information,
The present invention relates to a method of activating a low-activity polymer material by contacting the surface with a specific hydrocarbon solvent and then irradiating the surface with ultraviolet rays of a specific wavelength.

0002

[Prior Art] When a low-activity polymer material such as propylene has a chemical structure in which the molecular chain is a saturated hydrocarbon type and has a high degree of crystallinity, the surface of the molded product is inactive and cannot be coated, printed, etc.
Difficult to adhere. For this reason, pretreatment is necessary before painting, printing, or adhering the surface. Fibers made of polymeric materials with a saturated hydrocarbon type chemical structure and high crystallinity also have low activity and are difficult to dye, requiring pretreatment before dyeing. In addition, it may be necessary to make the surface of a molded article of a polymeric material having a hydrophobic chemical structure hydrophilic. In this case, surface treatment is required to make the surface of the molded object hydrophilic.

[0003] For these purposes, the following methods are conventionally used for surface activation treatment. First, sandblasting, solvent treatment, chromic acid mixture treatment, flame treatment, corona discharge treatment, plasma treatment, surface functional group imparting method, surface photografting method, etc. were proposed as surface pretreatment methods for painting, printing, and adhesion. Although it has been
Neither method is satisfactory.

[0004] Sandblasting is a method of roughening the surface of a material by bombarding the material surface with a granular abrasive at high speed. Granular abrasives contaminate the work environment and products. For this reason, it is necessary to wash the surface of the material with water before painting. Additionally, the surface becomes opaque due to the treatment, making it impossible to remove the abrasive material that has dug into the surface. In the solvent treatment, the polypropylene molded product is left in a halogenated hydrocarbon vapor heated to about 80° C. for a short time to swell and etch the amorphous portion on the surface of the molded product. When treated with this method, it is necessary to paint with an undercoat containing chlorinated polypropylene. Furthermore, if the coating is not applied immediately after treatment, the treatment effect will be lost in a short period of time. The molded product may be deformed due to processing. After painting, heating is required to remove residual solvent. This method is dangerous because it uses heated steam of halogenated hydrocarbons, and equipment corrosion can occur. Chromic acid mixture treatment is as follows: Chromic acid mixture (75 parts of potassium dichromate, 120 parts of water, 1,500 parts of concentrated sulfuric acid)
The material to be treated is heated to about 100°C and the object to be treated is immersed in it for about 5 minutes. The burden required to detoxify treated waste liquid is large. Flame treatment is an oxidizing flame (
The surface of the molded product is treated at a temperature of 1,000 to 2,500°C. Deformation and melting may occur due to heat.

[0005] Corona discharge treatment is a method in which a film or a film-like molded product is passed through a gap between an electrode and a metal roll, and a high voltage is applied. Processing of molded objects other than film-like objects is not possible. Plasma treatment involves applying low-temperature plasma to the plastic surface. Chemical changes occur on the surface due to the ionized gas and ultraviolet rays. Oxygen or air plasma is used, but the disadvantage is that the processing equipment is expensive. Methods for imparting surface functional groups include a method of irradiating ultraviolet rays in chlorine gas and then treating with alkali. The problem is that it uses extremely dangerous chlorine gas. Examples of the surface photografting method include a method in which benzophenone is kneaded into a polypropylene film and acrylamide is photograft-polymerized in an oxygen-blocked atmosphere. When considering economic efficiency, the difficulty is that the treatment process is complicated. From the above points, the development of new treatment methods has become a major technical challenge.

Next, as a pretreatment method for dyeing, the following method has been proposed for polypropylene fiber, which is a typical low-activity polymer material. (1) A method of oxidizing the surface using nitrogen dioxide, (2) A method of chlorinating the surface, and a method of further chlorinating the surface and subsequently treating it with an amine.
(3) A method of sulfonating the surface with fuming sulfuric acid, etc.
Further sulfonation followed by treatment with an amine, (4)
A method in which chlorosulfonation is performed under ultraviolet irradiation using sulfur dioxide gas and chlorine gas, followed by amine treatment. (5) Sulfolauric acid, sulfosalicylic acid, etc. are attached to polypropylene from the outside, heated, and transferred to the inside to some extent. A method of further treating this with an amine after fixing it with
) A method of treating with alkylamine, pyrrole, naphthylamine, etc., (7) A method of grafting with vinylpyridine or isopropenylpyridine, (8) Vinyl chloroacetate,
Examples include a method in which vinyl sulfonic acid or the like is grafted and then treated with an amine, (9) resin processing using an emulsion based on chlorosulfonated polyolefin, and (10) a method in which silicon tetrachloride is impregnated. However, none of these methods has been industrialized because the dyeing does not progress sufficiently, they are low in safety, and are low in economic efficiency.

[0007]

SUMMARY OF THE INVENTION The present invention overcomes the various drawbacks found in the surface treatment of low-activity polymeric substances, and
The purpose is to provide an excellent activation processing method.

[0008]

[Means for Solving the Problems] According to the present invention, the boiling point 1
A kerosene fraction in the range of 50 to 300°C is heated to a pressure of 10 to 100 kg/cm using a metal catalyst for nuclear hydrogenation of aromatic nuclei.
2. Nuclear hydrogenation treatment at a temperature of 150 to 300°C,
Next, a molecular sieve made of synthetic zeolite is used to separate and remove at least a portion of the n-paraffins in the kerosene fraction, and the resulting residual oil is fractionated by precision distillation to produce essentially naphthalene and biphenyl. Boiling point 150-300℃, preferably 210-250℃
A solvent consisting of a hydrocarbon mixture fraction in the range of (hereinafter referred to as
(referred to as "the solvent of the present invention") is brought into contact with the surface of a low-activity polymeric substance, and the surface of the low-activity polymeric substance is
There is provided a method for activating the surface of a low-activity polymeric material, which comprises irradiating ultraviolet light with a main working wavelength of 0 Å or less, preferably 1,849 Å.

[0009] The low-activity polymer material as used in the present invention means a resin mainly composed of a low-activity polymer material, preferably a homopolymer or copolymer of olefins such as ethylene, propylene, butene, etc. , more preferably the following substances. That is, (A) a low crystalline polyolefin resin with a crystallinity of less than 50% by X-rays, 100 to 0;
% by weight, preferably 100-5% by weight, more preferably 100-10% by weight, and (B) a highly crystalline polyolefin resin with a crystallinity of 60% or more by X-rays 0-100
% by weight, preferably 0-95% by weight, more preferably 0
-90% by weight of polyolefin resins and compositions thereof.

[0010] Examples of the low crystalline polyolefin resin (A) include the following various compounds. (a) Density less than 0.940 g/cm3, preferably 0.940 g/cm3.
Polyolefins such as homopolymers of ethylene, propylene, butene-1, etc., or copolymers mainly composed of these, such as linear low-density polyethylene, ultra-low-density polyethylene, etc., of 930 g/cm3 or less. (b) Copolymers of ethylene and polar monomers such as vinyl esters and unsaturated carboxylic acids, such as ethylene-vinyl acetate copolymers (EVA) and ethylene-(meth)acrylate copolymers. (c) Ethylene copolymer rubber or diene rubber, such as ethylene-propylene rubber, ethylene-propylene-diene rubber, SBR, NBR, BR, IIR, IR, etc. (d) In the above (a), (b), (c) or a mixture thereof, an unsaturated monobasic acid such as (meth)acrylic acid, an unsaturated dibasic acid such as maleic acid or its anhydride, or a derivative thereof Resin modified by etc. For example, the highly crystalline polyolefin resin (B) has a density of 0.9.
Examples include medium/high density polyethylene of 40 g/cm3 or more, crystalline polypropylene, polybutene-1, and poly4-methyl-pentene-1.

[0011] For the above-mentioned polymeric material used in the present invention, known antioxidants or heat stabilizers (hindered phenol type, phosphite type, hydroquinone type, thioether type, etc.), as long as they do not impair the purpose of the present invention. Adding ultraviolet absorbers (benzotriazole, resorcinol, salicylate, etc.), dyes or pigments, flame retardants, antistatic agents, nucleating agents (crystallization accelerators), modifiers, lubricants, mold release agents, etc. be able to. The above additives may be used in combination.

[0012] Also, for the purpose of improving physical properties or for other purposes,
Inorganic or organic fillers such as calcium oxide, magnesium oxide, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, calcium silicate, magnesium silicate, calcium sulfate,
Inorganic materials such as calcium carbonate, barium sulfate, calcium sulfite, talc, mica, clay, sericite, silica, alumina, glass, basic magnesium carbonate, dolomite, pilsonite, graphite, potassium titanate, glass fiber, carbon fiber, and various whiskers filler and/or
Organic fillers such as wood flour, cellulose fibers, synthetic fibers, melamine powder, or mixtures thereof may also be added.

The solvent used in the present invention has a boiling point of 15
It is obtained from a product obtained by hydrogenating a kerosene fraction in the range of 0 to 300°C using a metal catalyst for nuclear hydrogenation of aromatic nuclei. As the hydrogenation catalyst, any conventionally known metal catalyst for hydrogenation of aromatic nuclei can be preferably used. For example, nickel, nickel oxide, nickel/diatomaceous earth, Raney nickel, nickel/copper, platinum, platinum oxide,
Platinum/activated carbon, platinum/rhodium, platinum/lithium/alumina, rhodium/activated carbon, palladium, cobalt, Raney cobalt, ruthenium, nickel/tungsten,
Tungsten sulfide/nickel sulfide/alumina, cobalt/molybdenum, etc. can be used satisfactorily.

[0014] The hydrogen pressure is 10 to 100 kg/cm2 and the temperature is 100 to 300°C. At a pressure lower than 10 kg/cm2 or at a temperature lower than 100°C, the hydrogenation reaction does not proceed sufficiently, and at a pressure higher than 100 kg/cm2 or at a temperature higher than 300°C, side reactions such as decomposition take priority, so both are not preferred. As for the reaction format, any method such as a batch method or a continuous/flow method may be used. By the above hydrogenation, the aromatic hydrocarbons in the kerosene fraction are nuclear-hydrogenated and become naphthenes, but normally 100% of the aromatic hydrocarbons contained are not nuclear-hydrogenated, and the above-mentioned Depending on the type of catalyst, reaction conditions, etc., a certain amount of aromatic hydrocarbons remains without being hydrogenated. Further, hydrogenation treatment often involves decomposition, isomerization, etc. as side reactions, and the products of these reactions are inevitably included in the hydrogenated kerosene fraction.

Following the above hydrogenation treatment, a molecular sieve made of synthetic zeolite is used to separate and remove at least a portion of the n-paraffins in the hydrogenated kerosene fraction to obtain a residual oil. Using a molecular sieve, n- is removed from a hydrocarbon mixture by repeated adsorption and desorption in the gas or liquid phase.
Methods for separating and obtaining paraffins have conventionally been widely implemented industrially as a method for producing n-paraffins as described below. That is, for example, using a molecular sieve made of synthetic zeolite with a large number of pores adjusted to 5 Å as a fixed bed, adsorption and desorption of n-paraffins are performed alternately in the liquid phase, and the molecular sieve that has adsorbed n-paraffins is N-paraffins are desorbed by washing with low molecular weight paraffin for desorption, and the mixed low molecular weight paraffins for desorption are separated by distillation and recycled.・TSF method (Texaco Selective Finishing Method), which adsorbs n-paraffins in the gas phase using desorption and washes out with low molecular weight paraffin during desorption, also 5
A molecular sieve made of synthetic zeolite of Å is used, but n
- Isosieve method, in which paraffins are adsorbed and desorbed onto molecular sieves by alternately repeating pressurization and depressurization;
Furthermore, using a method that combines vapor phase and liquid bed methods, the adsorption of n-paraffins onto a molecular sieve made of synthetic zeolite with 5 Å pores is carried out continuously in the liquid bed in the adsorption device, and the desorption is carried out using a method that combines vapor phase and liquid bed methods. Examples include the Esso method, which operates at a higher temperature than the adsorption device in a regenerator, and the regenerated molecular sieve is recycled from the regenerator back to the adsorption device. N-paraffins can be separated by any of these methods using molecular sieves made of synthetic zeolite having pores of 5 Å.

Generally, in the separation of n-paraffins,
Theoretically, only n-paraffins should be separated, but depending on the method, hydrocarbons other than n-paraffins may also be separated along with n-paraffins, resulting in a residual oil. The content of components other than n-paraffins may vary. Taking these points into consideration, there is a method for industrially separating n-paraffins that uses urea crystals, but the method of the present invention uses
The method described above using molecular sieves made of synthetic zeolites with pores of 5 Å is suitable.

After the n-paraffins are separated from the kerosene fraction hydrogenated as described above to obtain a residual oil, this residual oil is then subjected to precision distillation. For example, using a precision distillation apparatus consisting of two or more distillation columns, light hydrocarbons are removed from the top of the first column, and the desired fraction is produced from the top of the second or subsequent columns. . Of course, if the separation efficiency such as the number of distillation stages is appropriate, light hydrocarbons and heavy hydrocarbons can be removed from the top and bottom of a precision distillation device consisting of one distillation column, respectively, and the desired hydrocarbons can be removed from the middle of the column. It is also possible to produce a fraction. Note that this precision distillation may be performed after the second stage of nuclear hydrogenation described below. A hydrocarbon mixture fraction having a boiling point in the range of 150 to 300°C, preferably 210 to 250°C is obtained using the precision distillation apparatus. The boiling point of the hydrocarbon mixture fraction of the present invention must be within the above range; if it is outside this range, the presence of each component and its content will be unbalanced, making it impossible to achieve the intended purpose. Therefore, it is undesirable. That is, when the boiling point is lower than 150° C., it is not preferable because it contains a large amount of harmful aromatic hydrocarbons such as benzene and toluene. On the other hand, a boiling point temperature exceeding 300° C. is not preferable because the effect of activating the surface of the low-activity polymer substance becomes insufficient, and the boiling point becomes too high, resulting in slow drying and strong residual odor.

The above hydrocarbon mixture fraction contains benzene,
It does not substantially contain toluene, etc., has a low content of other aromatic hydrocarbons, and in particular does not substantially contain naphthalene and biphenyl. However, in order to ensure higher safety in the present invention, for example to make it substantially free of all types of aromatic hydrocarbons, the residual oil is subjected to a second hydrogenation treatment. , it is also possible to remove aromatic hydrocarbons. The hydrogenation performed in the second stage can be performed in the same manner as the nuclear hydrogenation in the first stage. Alternatively, nuclear hydrogenation may be performed under milder conditions, ie, lower temperature or lower pressure. The metal catalyst for nuclear hydrogenation used in the second stage does not necessarily have to be the same as that in the first stage, and may be a different catalyst. In any case, the hydrogenation conditions may be appropriately selected from the above-mentioned hydrogenation conditions. Next, after the second stage of nuclear hydrogenation, precision distillation is performed as necessary, as described above. In the same manner as above, the boiling point is 150 to 300°C, preferably 21°C.
A hydrocarbon mixture fraction in the range 0-250°C is obtained. The solvent of the present invention consists of the fraction obtained as described above, and this fraction is a hydrocarbon fraction that has a low content of aromatic hydrocarbons or is substantially free of aromatic hydrocarbons.

In the present invention, as described above, the surface of a low-activity polymeric substance is brought into contact with the solvent of the present invention, and then the surface of the polymeric substance is irradiated with ultraviolet rays. In this case, the low-activity polymeric substance can be a molded product in various shapes such as a film, plate, fiber, etc. In addition to the immersion method, there are methods such as spraying and coating to bring the solvent into contact with the surface of the polymeric material.Also, when the surface of the polymeric material comes into contact with the solvent, ultrasonic waves are applied and the polymeric material is It is also possible to promote the sorption of solvents onto material surfaces. When bringing the solvent of the present invention into contact with the surface of a polymeric material, it is preferable to heat the surface of the polymeric material in advance. This heating temperature is preferably as high as possible without causing swelling or deformation of the polymeric substance.
For example, for polyolefin resins, the temperature is 90°C or lower, 30°C or higher, preferably 50°C or higher. The contact time is within 20 minutes, preferably from 5 seconds to 5 minutes. Further, in the present invention, a preheated solvent can be brought into contact with the surface of the polymeric substance.

[0020] In the present invention, the ultraviolet rays irradiated onto the surface of the polymeric substance must have a wavelength of 2,000 Å or less, and in particular, the main wavelength of action must be 1,849 Å. The stronger the intensity of the ultraviolet rays, the better, but in general,
700-15,000 mJ/cm2, preferably 1,0
It is in the range of 00 to 10,000 mJ/cm2.

[0021] When carrying out the present invention, the molded article made of a polymeric substance after irradiation with ultraviolet rays can be directly subjected to painting, printing, or adhesion. Further, the fiber or cloth after irradiation with ultraviolet rays can be dyed as is. If necessary, after the surfaces are subjected to static electricity removal treatment, painting, printing, adhesion, or dyeing is performed.

When treated with the solvent of the present invention, additives such as antioxidants and relatively small molecular weight components of the polymeric substance are eluted from the surface of the polymeric substance, and the surface of the polymeric substance is It is thought that the surface becomes rougher and becomes more activated along with the activation effect of ultraviolet irradiation. In order to exhibit such an effect, it is important that the solvent has an appropriate dissolving power. Since the solvent of the present invention hardly contains aromatic hydrocarbons and does not contain tetralin or decalin, it does not have too strong a dissolving power, and there is no risk of causing swelling and reducing strength. Furthermore, since it is composed of multiple components, it has a better balance of dissolving power than single-component solvents.

[0023]

EXAMPLES Next, the present invention will be explained in more detail with reference to examples. Solvent production example Boiling point range 150-300℃ obtained by distillation of crude oil
kerosene fraction (paraffins 65% by weight, naphthenes 25% by weight)
weight%, aromatic 10% by weight) at 280℃, 90kg/c
Under the conditions of m2, nuclear hydrogenation is carried out using a Ni-W catalyst for nuclear hydrogenation of aromatic hydrocarbons as a catalyst, and the obtained product is converted into molecules with 5 Å pores made of synthetic zeolite using the Molex method. The n-paraffins were separated by feeding into a separation column packed with sieves. The obtained residual oil fraction with reduced n-paraffins was then subjected to precision distillation using a two-column precision distillation apparatus to obtain a hydrocarbon mixture fraction with a boiling point of 210 to 240°C. Table 1 shows the properties of the solvent thus obtained.

[0024]

[Table 1]

Example 1 Isotactic polypropylene (crystallinity 80%, density 0.910 g/cm3, melt flow rate 10 g/cm3)
10min) 65% by weight, ethylene-propylene rubber (crystallinity 5% or less, density 0.860g/cm3, Mooney viscosity (100°C) 30) 25% by weight, and talc 10% by weight. An injection molded plate was produced. This molded plate was immersed in the above solvent at 40°C for 3 minutes. At this time, 28 kHz ultrasonic waves were irradiated. Then, it was dried at 80℃ for 5 minutes using a hot air circulation dryer.
After drying for a minute, use a low-pressure mercury lamp (product name: SUV-1).
10.Using a Sen special light source (manufactured by Sen Special Light Source Co., Ltd.), ultraviolet rays were irradiated for 5 minutes from a distance of 5 cm in an air atmosphere. The low-pressure mercury lamp used here was manufactured using synthetic quartz, which has a light transmittance of 85% or more at a wavelength of 1,850 Å. Approximately 30 minutes after the above treatment, the surface of the board was coated by a spray coating method using an acrylic resin paint containing an acrylic ester as a main component and a ketone solvent as a dispersion medium. The coating film formed on the surface of the plate was uniform and beautiful. Furthermore, after drying in an air atmosphere at room temperature for about 24 hours, the adhesion of the coating film was examined. Adhesion is expressed by cross-cutting the coating film to a width of 2 mm, pressing cellophane tape (Mitsubishi Uni Cellophane Tape 18) onto the coating film, and determining the proportion (percentage) of the number of lines remaining after peeling it off. However, the result was 98, which was good.

Example 2 A coating film formed in the same manner as in Example 1 was dried in an air atmosphere at room temperature for about 24 hours, and then dried at 20°C x 10
It was immersed in toluene for 10 minutes. When the adhesion of the same coating film was examined, the result was 97, which was good with almost no difference from the result of Example 1.

Comparative Example 1 A coating film was formed in the same manner as in Example 1, except that dipping with a solvent was not performed. The adhesion was 0, which was a significantly poor result.

[0028]

[Effects of the Invention] The unique effects produced by the present invention are as follows. (1) The polymeric substance treated according to the present invention is beautiful because the coating film, printed film, dyeing, etc. that adhere to the surface have good uniformity. The dyeing is strong. (2) The treatment method does not involve complicated chemical operations, and there is no post-treatment process such as washing with water or undercoating.
The number of steps is small and the processing time is short. (3) Since chlorine gas and high-temperature halogenated hydrocarbon vapor are not used in the treatment, there is little danger. (4) Ultraviolet irradiation equipment is inexpensive, and equipment costs are relatively low. (5) Unlike flame treatment, there is no risk of deforming or melting the surface. (6) Unlike corona discharge treatment, molded bodies other than those in film form can also be treated. (7) The irradiation time is short because the main working wavelength is ultraviolet rays of 1,849 Å.

Claims (2)

[Claims] Claim 1: A kerosene fraction having a boiling point in the range of 150 to 300°C is subjected to nuclear hydrogenation treatment using a metal catalyst for nuclear hydrogenation of aromatic nuclei at a pressure of 10 to 100 kg/cm2 and a temperature of 150 to 300°C. Then, by separating and removing at least a portion of the n-paraffins in the kerosene fraction using a molecular sieve made of synthetic zeolite, the residual oil obtained is fractionated by precision distillation to obtain substantially naphthalene and A solvent consisting of a fraction of a hydrocarbon mixture that does not contain biphenyl and has a boiling point in the range of 150 to 300°C, preferably 210 to 250°C, is brought into contact with the surface of a low-activity polymeric substance, and the wavelength 1. A method for activating the surface of a low-activity polymeric material, which comprises irradiating ultraviolet light with a main wavelength of 2,000 Å or less, preferably 1,849 Å. 2. The method for activating the surface of a low-activity polymeric substance according to claim 1, wherein the low-activity polymeric substance is a polyolefin.