JPH07116364B2 - Surface treatment method - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a surface treatment method, and more specifically, to a surface of various films used as a base material for various packaging materials, heat-sensitive recording magnetic wrapping paper and adhesive tapes. The present invention relates to a surface treatment method capable of improving slipperiness.

[Technical Background of the Invention and Problems Thereof] Films made of plastics such as polyethylene, polyethylene terephthalate and polypropylene have been widely used as base materials for packaging materials, magnetic recording tapes and adhesive tapes. The plastic film is required to have appropriate slipperiness according to its application because of its use requirements. As a method of imparting slipperiness to a plastic film, a method of forming a coating layer having slipperiness on the film surface has been performed, and various compositions capable of forming this coating layer have been proposed. Such a composition is obtained by dispersing powder, which is a main component capable of imparting slipperiness, in a binder resin. By forming a coating layer made of this composition on the plastic surface and making the plastic surface not a smooth surface but a surface having fine irregularities, the contact area between the plastic film and another article can be made smaller. As a result, the slipperiness of the film can be improved. As the powder which is the main component capable of imparting slipperiness in such a composition,
For example, JP-A-57-130234, JP-A-58-161135, JP-A-57-53825 and JP-A-58-2415 disclose examples using inorganic powders, and further Many have disclosed that the particle size was limited.

However, those containing these inorganic powders not only cannot impart sufficient slipperiness to the film, but also when the coating layer containing the same comes into contact with other articles and rubbed against them, Since the binding force with the binder resin is insufficient, the so-called powder falling phenomenon in which the inorganic powder is missing from the film is likely to occur. This phenomenon is due to the fact that inorganic powders generally have a wide variety of particle shapes and are not uniform, and that the particle size distribution is wide, and as a result, the unevenness of the surface is not uniform, so the slipperiness is partially It is because they are different. Therefore, there is a problem that stable running performance cannot be obtained during use.

As a method for solving such a problem, JP-A-60-121515
In the publication, a technique using a benzoguanamine resin powder instead of the above-mentioned inorganic powder is disclosed, and the slipperiness of the film and the ease of mixing with the binder resin at the time of production are compared to the case of using the inorganic powder. Has been improved. However, even if this method is applied, the improvement of the slipperiness of the film cannot be said to be sufficient, and the problem of powder falling during use has not yet been solved.

[Object of the Invention] It is an object of the present invention to provide a surface treatment method capable of improving the slipperiness of the surface of various films such as plastic films and papers, and particularly improving the running stability of the film.

[Structure of the Invention] The surface treatment method of the present invention comprises a spherical polymethylsilsesquioxane powder in which 80% or more of particles are in the range of ± 30% of the average particle diameter and a thermoplastic resin or a thermosetting resin. An organic solvent solution type or emulsion type surface treatment agent containing a binder resin is applied so that the thickness of the binder resin layer after the surface treatment is smaller than the particle diameter of the true spherical polymethylsilsesquioxane powder. Characterize.

The surface treatment method of the present invention forms a coating layer on the surface of various films using the surface treatment agent to improve the slipperiness of the film and the running stability.

The spherical polymethylsilsesquioxane powder used in the present invention constitutes a powder component alone or in a mixed system with other powder components, and contributes to improvement of the slip property of the film surface and its directional stability. It is an ingredient.

Such a spherical polymethylsilsesquioxane powder has a substantially spherical shape in which the shape of each particle is independent, and 80% or more in the particle size distribution is within the range of ± 30% of the average particle diameter,
It is manufactured as follows. That is, methyltrialkoxysilane and / or its partial hydrolysis-condensation product or a mixture of methyltrialkoxysilane and / or its partial hydrolysis-condensation product and an organic solvent is used as the upper layer, and an aqueous solution of ammonia or amine and / or ammonia or A mixed solution of an amine and an organic solvent is used as a lower layer, and a hydrolysis / condensation reaction between a methyltrialkoxysilane and / or its partially hydrolyzed condensate and an alkaline solution is gradually carried out at the interface between these layers. As the reaction proceeds, spherical particles are produced and transferred to the lower alkaline solution layer, and the lower layer changes to milky white.

The stirring conditions in this reaction vary depending on the shape of the stirring blade, the composition of the alkaline solution, etc., but in order to obtain the target spherical particles having a narrow particle size distribution, the stirring should be performed at a speed of about 2 to 100 rpm. Preferably 5 more preferably
~ 50r.pm.

Under the above conditions, the reaction is continued until the upper layer of methyltrialkoxysilane disappears, and stirring is further continued.
The stirring time and temperature vary depending on the production amount, etc., but 1 to 10 hours is appropriate, and if necessary, about 50
The temperature may be raised to about ° C.

Then, the dispersion is extracted through a wire mesh, dehydrated by a centrifugal separation method or a centrifugal excess method, the obtained paste-like material is heated and dried at 100 to 220 ° C., and then crushed using a jet mill grinder or the like. As a result, at least 95% or more of polymethylsilsesquioxane powder having a substantially spherical shape can be obtained.

The particle size of the true spherical polymethylsilsesquioxane powder thus obtained is not particularly limited,
It is preferable that the particle size is μm because a spherical powder can be easily obtained, and 0.5 to 20 μm is more preferable for the same reason.

As the other powder component used when the powder component is a mixed system, for example, polymethylsilsesquioxane powder having a different particle size from the spherical polymethylsilsesquioxane powder which is a constituent component of the surface treatment agent ( It does not need to be spherical), benzoguanamine resin powder, organic fine powder such as tetrafluoroethylene resin powder, carbon black,
Silicon oxide, titanium oxide, aluminum oxide, chromium oxide, silicon carbide, calcium carbide, zinc oxide, α-Fe
₂ O ₃ , talc, kaolin, calcium sulfate, boron nitride,
Inorganic fine powders such as zinc fluoride, molybdenum dioxide, and calcium carbonate can be blended. Among them, spherical polymethylsil having different particle diameters because of good dispersibility and excellent heat sealability. A sesquioxane powder is preferred. The particle diameter of such other powder component must be smaller than the particle diameter of the true spherical polymethylsilsesquioxane powder.

The mixing ratio of the spherical polymethylsilsesquioxane powder and the other powder components when the powder component is a mixed system is 100% by weight of the spherical polymethylsilsesquioxane powder, and the other powder component is 50 to 100 parts by weight, preferably 1
0 to 50 parts by weight. When the blending ratio of other powder components is too low, for example, a surface-treated film is
Adhesion of the bonding surface is poor when it is used by bonding it to another film through the treated surface, and when the blending ratio is too large, the adhesive strength decreases when bonded in the same manner. Not preferable.

A thermoplastic resin or a thermosetting resin is used as the binder resin that constitutes the surface treatment agent used in the present invention together with the powder component made of the above spherical spherical polymethylsilsesquioxane powder.

The thermoplastic resin used as the binder resin has a softening temperature of 150 ° C. or lower, an average molecular weight of 10,000 to 200,000, and a degree of polymerization of about 200 to 2,000, for example, acrylic acid ester-acrylonitrile copolymer, acrylic acid ester- Vinylidene chloride copolymer, acrylic acid ester-styrene copolymer, methacrylic acid ester-acrylonitrile copolymer, methacrylic acid ester-vinylidene chloride copolymer, methacrylic acid ester-styrene copolymer,
Urethane elastomer, polyvinyl fluoride, vinylidene chloride-acrylonitrile copolymer, acrylonitrile-butadiene copolymer, polyamide resin, polyvinyl butyral, styrene-butadiene copolymer, polyester resin, chlorovinyl ether-acrylic acid ester copolymer, amino Examples thereof include resins, various synthetic rubber-based thermoplastic resins, and mixtures thereof.

The thermosetting resin or reactive resin has a molecular weight of 200,000 or less in the state of a coating liquid, and is condensed after coating and drying,
Those which are insolubilized by a reaction such as addition can be used. Among these resins, those which do not soften or melt before being thermally decomposed are preferable. Specifically, for example, phenol resin, phenoxy resin, epoxy resin, polyurethane curable resin, urea resin, melamine resin, alkyd resin, silicone resin, acrylic reaction resin, vinyl chloride-vinyl acetate resin, methacrylate copolymer. And a mixture of diisocyanate prepolymer, a mixture of high molecular weight polyester resin and isocyanate prepolymer,
Examples thereof include urea formaldehyde resin, a mixture of polyester polyol and isocyanate, polycarbonate type polyurethane, polyamide resin, a mixture of low molecular weight glycol / high molecular weight diol / triphenylmethane triisocyanate, and a mixture thereof.

As the electron beam irradiation curable resin, an unsaturated prepolymer,
For example, maleic anhydride type, urethane acryl type, polyester acryl type, polyether acryl type, polyurethane acryl type, polyamide acryl type, etc., or as a polyfunctional monomer, ether acryl type, urethane acryl type, phosphate ester acryl type, aryl type , Hydrocarbon type and the like.

The blending ratio of the powder component and the binder resin consisting of spherical polymethylsilsesquioxane powder constituting the surface treatment agent used in the present invention is, relative to 100 parts by weight of the binder resin, the powder component is 0.01 to 30 parts by weight. Part, preferably
0.05 to 15 parts by weight. When the blending ratio of the powder component is too small, the slipperiness of the film surface after the treatment cannot be improved until it is sufficiently satisfied, and when it is too large, the slipperiness is already improved. Not only that, but the strength of the coating layer formed is reduced.

The surface treatment agent used in the present invention further enhances the strength of the coating layer formed on the film surface (bonding force between the spherical polymethylsilsesquioxane powder and the binder resin), and further improves the slip property of the film. In order to achieve this, it is preferable to add a curing agent. Such a curing agent can be appropriately selected depending on the application of the film. Further, such a curing agent is not necessary when the surface treatment agent of the present invention is applied as an adhesive component of an adhesive tape.

The surface treatment agent used in the present invention, if necessary, a dispersant,
Additives such as lubricants and antistatic agents can be added. Examples of the dispersant include lecithin; caprylic acid,
Fatty acids having 8 to 18 carbon atoms such as capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, elaidic acid, linoleic acid, and linolenic acid (fatty acids represented by the formula R-COOH. Has 7 carbon atoms
Represents 17 saturated or unsaturated alkyl groups); metal soaps composed of the above-mentioned fatty acid alkali metals (Li, Na, K, etc.) or alkaline earth metals (Mg, Ca, Ba, etc.) it can. In addition to these, higher alcohols having 12 or more carbon atoms, and sulfuric acid ester can also be used. Also,
A commercially available general surfactant can also be used. These dispersants may be used alone or in combination of two or more. As the lubricant, for example,
Various silicone oils, graphite, molybdenum disulfide, tungsten disulfide, 12 to 16 carbon atoms consisting of monobasic fatty acids and monohydric alcohols with 21 to 20 carbon atoms
Examples include 23 fatty acid esters (wax) and the like. Examples of the antistatic agent include conductive powders such as carbon black, graphite, tin oxide-antimony oxide compounds, and titanium oxide-tin oxide-antimony oxide compounds; natural surfactants such as savonine; alkylene oxide compounds. Glycerin-based, glycidol-based, etc. nonionic surfactants; higher alkylamines, quaternary ammonium salts, pyridine and other heterocycles, cation surfactants such as phosphonium or sulfonium compounds; carboxylic acids, sulfonic acids, phosphoric acid, sulfuric acid Anionic surfactants containing acidic groups such as ester groups and phosphoric acid ester groups; amphoteric surfactants such as amino acids, aminosulfonic acids, sulfuric acid or phosphoric acid esters of amino alcohols, and the like can be mentioned.

The surface treatment agent used in the present invention is a spherical spherical polymethylsilsesquioxane powder, and if necessary, other powder components and various additives and binder resins are put in an appropriate container, and then a ball mill, a triple roll, an attritor. Alternatively, it can be obtained by stirring and mixing so as to be uniform using a disperser such as a sand mill. In addition, since the spherical polymethylsilsesquioxane powder has extremely excellent dispersibility with the binder resin described above, when the powder component is the spherical polymethylsilsesquioxane powder alone, it looks like a homomixer. It can be easily dispersed and mixed even with various dispersers.

The surface treatment agent used in the present invention is an organic solvent solution type or emulsion type dissolved in an organic solvent, depending on the binder resin used. Examples of the diluting solvent in this case include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, ethylene glycol monoacetate; ethylene glycol dimethyl ether, diethylene glycol. Ethers such as monoethyl ether, dioxane and tetrahydrofuran; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as methylene chloride, ethylene chloride, carbon tetrachloride, chloroform and dichlorobenzene. it can. Further, in order to obtain a surface treatment agent in an emulsion state, after adding water to the spherical polymethylsilsesquioxane powder and the like and the surfactant and uniformly dispersing by ultrasonic waves, the binder resin as it is or It can be obtained by adding a binder resin emulsion and mixing.

When the film surface is treated using the surface treating agent of the present invention, for example, it is applied by a bar coater or the like so as to have a uniform thickness, and then usually dried by leaving it at room temperature, It is carried out by curing to form a coating layer.

The structure of the film thus surface-treated will be described with reference to FIGS. 1 and 2. 1 and 2
Figure is a cross-sectional view of the surface-treated film,
Here, FIG. 1 shows the case where the powder component is a true spherical polymethylsilsesquioxane powder alone, and FIG. 2 shows the case where the powder component is a mixed system. That is, the film after the surface treatment is present on the film 1 in a state in which the binder resin layer 2 made of the binder resin (in the case of FIG. 2, the binder resin and the other powder component 4) and the binder resin layer 2 are projected. True spherical polymethylsilsesquioxane powder 3
It has a structure in which a coating layer made of is formed. Also,
The other powder component 4 may be one that protrudes from the binder resin layer 2. As described above, on such a film surface, the particle diameter of the spherical polymethylsilsesquioxane powder 3 is smaller than the thickness of the binder resin layer 2 (when the binder resin layer 2 contains another powder component 4). Is necessarily larger than both the thickness of the binder resin layer 2 and the particle diameter of the other powder component 4, but in such a case, the particle diameter of the spherical polymethylsilsesquioxane powder is too large. When it is too much, the powder is apt to be lost, and it is difficult to continuously provide stable slipperiness. Therefore, it is preferable that the true spherical polymethylsilsesquioxane powder has an average particle size of 4 times or less the thickness of the binder resin layer. The thickness of the binder resin layer is not particularly limited and is usually 0.1 μm or more, preferably 0.2 μm or more, but this thickness is a particle with the spherical polymethylsilsesquioxane powder described above. It can be determined in relation to the diameter.

The surface treatment method of the present invention can be applied as a surface treatment method for various films such as paper, polyethylene terephthalate film, polypropylene film, polyethylene film, polyvinyl chloride film, cellulose acetate film, polycarbonate film and polyvinylidene fluoride film. .

Further, the surface treatment agent used in the present invention can be used as an adhesive component of an adhesive tape. For example, the film treated by the surface treatment method of the present invention, depending on the application,
It can be adhered to another film made of the same or different material through the coating layer on the film, and
Similarly, a plurality of surface-treated films can be laminated with the covering layer interposed therebetween. In the case of using such a film, as the powder component, it is possible to blend the above-mentioned other powder component together with the spherical polymethylsilsesquioxane powder, which is excellent in adhesion when bonded to another film. It is preferable because

[Effects of the Invention] As described above, the surface treatment method of the present invention can improve the slipperiness of the surface of a plastic film, paper or the like, and can maintain the slipperiness. In addition, the polymethylsilsesquioxane powder, which is a useful component capable of imparting slipperiness in the surface treatment agent, has a substantially spherical shape, so that a uniform uneven state can be formed on the entire surface of the film, so that stable sliding is achieved. It is possible to impart sex.
This is extremely superior to the fact that the conventional treatment with a surface treatment agent could not impart stable slipperiness because the unevenness of the treated surface was uneven. Furthermore, since the polymethylsilsesquioxane powder has a true spherical shape with a uniform particle diameter, the problem of powder falling rarely occurs.

[Examples] Hereinafter, the present invention will be described with reference to Examples. In addition, all "parts" in Examples and Comparative Examples represent "parts by weight".

Synthesis Example 1 4,000 parts of water and 50 parts of 28% aqueous ammonia solution were charged into a four-necked flask equipped with a thermometer, a reflux condenser and a stirrer.
Stirred at pm for 10 minutes to make a homogeneous aqueous ammonia solution.
To this aqueous ammonia solution, 600 parts of methyltrimethoxysilane of 10 ppm in terms of chlorine atom was quickly added so as not to mix in the aqueous ammonia solution while rotating the stirrer at 5 rpm, and the upper layer was methyltrimethoxysilane layer, and the lower layer was added. It was made to have a two-layer state of an aqueous ammonia layer. Then, the hydrolysis / condensation reaction was allowed to proceed at the interface between methyltrimethoxysilane and the aqueous ammonia solution while maintaining the two-layer state by setting the stirring speed of the stirrer to 20 rpm. As the reaction proceeded, the reaction product gradually settled in the lower layer, the reaction product floated in the lower layer and became cloudy, and the methyltrimethoxysilane layer in the upper layer gradually thinned and disappeared in about 3 hours (visual observation). Confirmed by). Further, the temperature was maintained at 50 to 60 ° C, the mixture was stirred under the same conditions for 3 hours, and then cooled to 25 ° C. Next, the precipitated product was filtered through a 100-mesh wire net, dehydrated by centrifugation to form a cake, and the cake layer was dried in a dryer at 200 ° C. This was crushed using a lab jet to obtain a white powder.

The polymethylsilsesquioxane powder thus obtained was observed with an electron microscope to find that it had a nearly spherical shape with a ratio of X-axis to Y-axis of the particle diameter of 1.0 to 1.2 and an average particle diameter of about 1.9. It was one of μm.

Synthesis Example 2 The amount of the 28% concentration aqueous ammonia solution in Synthesis Example 1 was 100%.
Partial spherical polymethylsilsesquioxane powder having an average particle diameter of 1.2 μm was obtained in the same manner as in Synthesis Example 1 except that the stirring speed after the two-layer state was changed to 15 rpm.

Synthetic Example 3 The amount of the 28% concentrated aqueous ammonia solution in Synthetic Example 1 was changed to 5
Partial spherical polymethylsilsesquioxane powder having an average particle diameter of 4.5 μm was obtained by the same method as in Synthesis Example 1 except that the stirring speed after the two-layer state was changed to 25 rpm.

Example 1 In a container, 25 parts of Dyanal BR88 (polymethylmethacrylate, trade name of Mitsubishi Rayon Co., Ltd.) and toluene 300
Parts, 200 parts of ethyl acetate and 475 parts of n-hexane were added, and then mixed evenly to obtain a mixed solution. Next, 0.3 part of the polymethylsilsesquioxane powder obtained in Synthesis Example 1 was added to 1000 parts of this mixed solution, and then mixed at 1000 rpm for 20 minutes in a homomixer. The polymethylsilsesquioxane powder obtained in Synthesis Example 1 was easily dispersed in the system to obtain a solution of the surface treatment agent of the present invention.

A solution of this surface treatment agent was applied onto a polyethylene terephthalate film support having a thickness of 50 μm using a bar coater # 12 (manufactured by Yoshimitsu Seiki Co., Ltd.) so that the thickness of the binder layer after drying would be 0.7 μm. , Then at room temperature 48
After standing for a time, a coating layer was formed. The following evaluations were performed on the film thus surface-treated. The results are shown in Table 1.

Appearance of coating layer: The dispersed state of the powder in the coating layer was visually observed.

Abrasion resistance: After the film was cut into two pieces, the respective coating layers were combined and lightly rubbed 100 times, and the state of the film surface was observed with an optical microscope.

Static friction function: Measured using a static friction coefficient meter HEIDEN-10 type (manufactured by Shinto Chemical Co., Ltd.).

Comparative Example 1 Instead of the polymethylsilsesquioxane powder obtained in Synthesis Example 1, homocal (calcium carbonate powder, particle size 0.3 μm,
A solution of a comparative surface treatment agent was obtained in the same manner as in Example 1 except that 1.0 part of Shiraishi Industry Co., Ltd. was used. Homocal was more difficult to disperse than the polymethylsilsesquioxane powder obtained in Synthesis Example 1. Next, the surface of the polyethylene terephthalate film was treated in the same manner as in Example 1 using the solution of the comparative surface treatment agent, and the same evaluation was performed. The results are shown in Table 1.

Examples 2-3 and Comparative Examples 2-3 Dianar BR88 20 parts, Acridic A-8 in a container.
/ 0-45 (acrylic polyol, manufactured by Dainippon Ink and Chemicals, Inc.) 11 parts, Vernock D-750 (isocyanate, manufactured by Dainippon Ink and Chemicals, Inc.) as a curing agent, 5 parts,
200 parts of toluene, 200 parts of ethyl acetate, and 64 parts of n-hexane were added as a solvent, and then mixed uniformly to obtain a mixed solution. Then, in 1000 parts of this mixed solution, the polymethylsilsesquioxane powder obtained in Synthesis Example 2 and the polymethylsilsesquioxane powder obtained in Synthesis Example 3 or homocal, Aerosil 130 in the compounding amounts shown in Table 2 were used. (Fumed silica, manufactured by Nippon Aerosil Co., Ltd.) was mixed and mixed in the same manner as in Example 1 to obtain a solution of the surface treating agent of the present invention and a solution of the comparative surface treating agent.

The surface of the polyethylene terephthalate film was treated in the same manner as in Example 1 except that the thickness of the binder layer after drying was adjusted to 0.5 μm using each of the solutions of the obtained Examples and Comparative Examples. Was evaluated. Second result
Shown in the table.

Examples 4 to 5 and Comparative Example 4 A spherical polymethylsilsesquioxane powder in an amount shown in Table 3 and 1.5 parts of Emulgen 920 (nonionic surfactant, manufactured by Kao Corporation) were put in a container and sufficiently charged. After mixing into
Furthermore, 300 parts of city water was gradually added. Then, ultrasonic waves were passed through this solution for 60 minutes to disperse the solution uniformly, and then Saran latex L-502 (vinylidene chloride latex, solid content 5
1000 parts of 0%, manufactured by Asahi Kasei Co., Ltd.) were added and mixed to obtain a uniform solution of the surface treatment agent of the present invention.

Further, as a comparative example, as shown in Table 3, a solution of a surface treatment agent for comparison was obtained in the same manner as in Example 3 except that 4.0 parts of Aerosil 200 was used instead of the spherical polymethylsilsesquioxane.

The thickness of the binder layer after drying each of the obtained solutions of Examples and Comparative Examples on a surface of a polypropylene film having a thickness of 22 μm subjected to corona discharge using a rod bar coater # 3 (manufactured by Yoshimitsu Seiki Co., Ltd.) Was 3 μm. After coating, the film was allowed to stand at room temperature for 48 hours, and the following tests were conducted on the film having the coating layer formed thereon.

Appearance of coating layer: same as in Example 1.

Static friction coefficient: same as in Example 1.

Dynamic friction coefficient: Rotating drum type surface measuring instrument (Shinto Kagaku)
Was used under the conditions of a rod diameter of 4 mm, a load of 30 g, and a rotation speed of 66.9 rpm.

Adhesion: In accordance with JIS Z-1515 blocking resistance test,
The heating conditions were 50 ° C. and 24 hours, and it was observed whether the two test pieces adhered.

Heat sealability: Using a sentinel heat sealer single-sided bar type, applying a load of 2 kgf / cm ² and heating each film at 140 ° C for 1 second to bring them into close contact with each other, a pulling speed of 300 mm / min using a tensile tester The tensile strength was measured with to evaluate the heat sealability. The evaluation was carried out as a relative value when the tensile strength of the polypropylene film not surface-treated was 100.

Examples 6 to 7 and Comparative Examples 5 and 6 As shown in Table 4, polymethylsilsesquioxane powder and Aerosil 200 were added to toluene and then mixed uniformly to obtain dispersions. In addition, in the case of Examples 6 and 7 and Comparative Example 5, the mixture was stirred and mixed with a homomixer, and in the case of Example 8 and Comparative Example 6, glass beads having a diameter of 2 mm were used as a dispersion medium and a sand grinder was used for 1,000.
Dispersion was performed by stirring and mixing for 60 minutes at rotation / minute.

Next, 100 parts of the silicone-based pressure-sensitive adhesive was added to and mixed with 100 parts of each of the dispersions to obtain surface treatment agent solutions of the present invention and comparison. The silicone pressure-sensitive adhesive has both ends blocked with dimethylhydroxysilyl groups,
The balance is dimethylsiloxane units, the viscosity at 25 ℃ is 500,
250 parts of 000 cp polydimethylsiloxane, consisting of (CH ₃ ) ₃ SiO _1/2 unit and SiO ₂ unit, and (CH ₃ ) ₃ SiO _1/2 unit of SiO ₂ unit 1
50% of resinous copolymer with a molar ratio of 0.65 mol
It was obtained by uniformly mixing 500 parts of a toluene solution and 250 parts of xylene.

Using the obtained surface treating agents, surface-treated polypropylene films were obtained in the same manner as in Examples 4 and 5, and the same evaluation test was conducted. The results are shown in Table 5.

[Brief description of drawings]

1 and 2 are cross-sectional views of a film treated with the surface treatment agent of the present invention.

Claims (1)

[Claims] 1. An organic solvent solution containing 80% or more of particles having a spherical polymethylsilsesquioxane powder having an average particle diameter within a range of ± 30% and a binder resin made of a thermoplastic resin or a thermosetting resin. Type or emulsion type surface treatment agent is applied such that the thickness of the binder resin layer after the surface treatment is smaller than the particle diameter of the true spherical polymethylsilsesquioxane powder.