JP2000328080A - Agent for low friction treatment of seat belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an agent for a low friction treatment of seat belts which agent gives a sufficiently high initial slidability to webbing fibers with coating a seat belt webbing with it, prevents the decrease of properties such as slidability, wear resistance and the like, with time, prevents the adhesion of dirt, and keeps its excellent storability even after a long time use. SOLUTION: This agent comprises (A) a polyurethane resin and (B) a polyurethane resin composition containing spherical hydrophobic silica fine particles having an average particle size of the primary particles of 0.01-5 μg which satisfy the conditions (i) when an organic compound which is liquid at room temperature and has a dielectric constant of 1-40 F/m and the silica particles are mixed and shaken at a mixing ratio of 5 to 1 in weight, the silica particles should be uniformly dispersed; (ii) after methanol is evaporated by heating from a dispersion of the silica particles in methanol and then the residue is kept at 100 deg.C for 2 hr, at least 20% of the initial primary particles should remain still as primary particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-friction treating agent coated on a seatbelt webbing, and more particularly, to a seatbelt effective for obtaining a seatbelt having good slipperiness and excellent storage properties. It relates to a low friction treating agent.

[0002]

2. Description of the Related Art Seat belts used for seats of automobiles, aircrafts, etc. are generally made by dyeing a seat belt webbing (a fabric obtained by weaving a yarn for a seat belt) and then abrasion resistance of the seat belt (abrasion resistance retention rate). ) And storage (the ability to pull out and store the seat belt)
It is produced by applying a resin coating to the dyed webbing.

[0003] As the coating resin used here, for example, a resin containing a urethane prepolymer block compound as a main component is known (Japanese Patent Publication No. 4-66948). In this case, the resin as described above is coated on the seat belt webbing and heat-treated to cause crosslinking, thereby increasing the surface hardness, improving wear resistance, and improving the initial slipperiness of the seat belt. It is intended to increase the value significantly and to maintain the desired level of slip, i.e. frictional properties, even after prolonged use.

[0004]

However, in the case of a seat belt coated with a resin, in particular, a seat belt coated with a cross-linking resin as described above, even if the surface hardness is increased, the abrasion resistance with time is increased. If the product has been used for a long period of time, the resin coated on the surface is gradually scraped off due to repeated rubbing with the through (made of nylon resin), which is a guide for assisting in and out of the seat belt. And filth gradually adheres to the belt surface. As a result, there is a large problem that the storage stability of the seat belt is significantly reduced with time.

[0005] Accordingly, an object of the present invention is to solve the above-mentioned problems in the prior art and to provide a sufficiently high initial slip property to webbing fibers, that is, excellent friction characteristics by coating a seat belt webbing, and to improve the aging property. To provide a low-friction treating agent for a seatbelt, which prevents deterioration of properties such as slipperiness and abrasion resistance and adherence of filth, thereby obtaining a seatbelt capable of maintaining excellent storage properties even after long-term use. It is in.

[0006]

In order to achieve the above object, the present invention provides (A) a polyurethane resin, and (B) the following conditions (i) and (ii): (i) a liquid at room temperature; When the organic compound having a dielectric constant of 1 to 40 F / m and the silica-based fine particles are mixed at a weight ratio of 5: 1 and shaken, the silica-based fine particles are uniformly dispersed in the organic compound; (Ii) After methanol is distilled off from a dispersion in which the silica-based fine particles are dispersed in methanol by heating with an evaporator,
When held at a temperature of 100 ° C. for 2 hours, the ratio of the amount of primary particles remaining as primary particles to the amount of primary particles originally present is 20% or more; 2. The low friction treating agent for a seat belt according to claim 1, wherein the polyurethane resin composition comprises a spherical hydrophobic silica fine particle having a particle size of 0.01 to 5 [mu] m.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The low friction treating agent of the present invention comprises (A)
It comprises a polyurethane resin composition containing a polyurethane resin and (B) spherical hydrophobic silica fine particles. <(A) Polyurethane-based resin> The polyurethane-based resin used in the friction reducing agent of the present invention may be a commonly used one, and is not particularly limited. Such a polyurethane resin can be easily obtained by reacting a polyol compound with a polyisocyanate compound in the presence or absence of an organic solvent or an aqueous solvent according to a conventionally known production method. The polyol compound used here may be a polyether polyol, a polyester polyol, other polyols, or a mixed polyol thereof as in the case of the usual polyol compound for a polyurethane resin.

Specifically, polyether polyols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3 -Butanediol, 1,4-butanediol, 4,4'-dihydroxyphenylpropane, 4,4'-dihydroxyphenylmethane, at least one of polyhydric alcohols such as pentaerythritol, propylene oxide, ethylene oxide, butylene oxide And a polyol obtained by adding at least one of styrene oxide and the like; and polyoxytetramethylene oxide.

As the polyester polyol, at least one of ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane, and other low-molecular polyols is used. , Glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid,
Preferable examples include a condensation polymer with dimer acid and at least one other low-molecular carboxylic acid or oligomer acid; ring-opening polymers such as propiolactone and valerolactone.

Other polyols include high molecular weight polyols such as polycarbonate polyols, polybutadiene polyols, hydrogenated polybutadiene polyols and acrylic polyols; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, hexanediol. And the like. The above polyol compounds are used alone or in combination of two or more.

On the other hand, examples of the polyisocyanate compound include those similar to the ordinary polyisocyanate compounds for polyurethane resins. Specifically, 2,4-
Tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,
Aromatic polyisocyanates such as 4'-diphenylmethane diisocyanate, p-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate; aryl fats such as xylylene diisocyanate Aromatic polyisocyanate; a carbodiimide-modified product or an isocyanurate-modified product of each of the above polyisocyanates is preferably exemplified. The above polyisocyanate compounds are used alone or in combination of two or more.

As the polyurethane resin (A), a urethane prepolymer obtained by reacting the above polyisocyanate compound with a low molecular weight polyol or polyamine so as to be a terminal isocyanate can also be used. Further, a polyurethane resin having a siloxane structure introduced by using a siloxane compound having active hydrogen as a part of the polyol compound can also be used. For example, an epoxy-modified siloxane, an amino-modified siloxane, an alcohol-modified siloxane, a mercapto-modified siloxane, a carboxyl-modified siloxane, a siloxane containing a silanol group, and the like, which react with polyols, polyamines, polycarboxylic acids, and the like to generate active hydrogen, may be mentioned.

The polyurethane resin as the component (A) can be prepared in the presence (ie, in an organic solvent or an aqueous solvent) or in the absence of an organic solvent or an aqueous solvent. This is advantageous because the spherical hydrophobic silica fine particles of the component (B) can be directly used for the application of the present invention simply by adding to the resulting solution. When preparing a polyurethane resin using an aqueous solvent, the free isocyanate group of the urethane prepolymer is
Secondary or tertiary alcohols, active methylene compounds, phenols, lactams, imidazoles, bisulfites and the like, aqueous solvents using blocked urethane prepolymers blocked with generally known blocking agents for isocyanate groups Can be prepared.

As the organic solvent, methyl ethyl ketone,
Methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, acetone, cyclohexane, tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol, toluene , Xylene, dimethylformamide, dimethyl sulfoxide, perchlorethylene,
Trichloroethylene, methyl cellosolve, butyl cellosolve, cellosolve acetate and the like, but preferred are methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, methyl acetate, ethyl acetate, Butyl acetate and the like. In dispersing the spherical hydrophobic silica fine particles in the polyurethane resin solution, a surfactant may be used.

Examples of the surfactant include alkylene oxide adducts of higher alcohols (octyl alcohol ethylene oxide / propylene oxide adducts, stearyl alcohol ethylene oxide / propylene oxide adducts, oleyl alcohol ethylene oxide adducts), and the like. Alkylene oxide adducts of polyhydric alcohol esters (ethylene oxide 25 in hydrogenated castor oil)
A molar adduct, a 20 molar adduct of sorbitan trioleate with ethylene oxide, etc.). When a surfactant is blended, the amount is usually 1 to 20 parts by weight based on 100 parts by weight of the polyurethane resin.

[0016] The polyurethane resin obtained as described above may contain various additives which are added to a normal urethane resin, if necessary, ie, a plasticizer such as dioctyl phthalate; an antioxidant; Coloring agents such as pigments and dyes; and curing catalysts (curing accelerators) such as organometallic compounds and amines. The amounts of these additives may be appropriately determined within a range that does not impair the effects of the present invention.

<(B) Spherical Hydrophobic Silica Fine Particles> The spherical hydrophobic silica fine particles used in the present invention are the following conditions (i) and (ii): (i) a liquid at room temperature and a dielectric constant of 1 to 40 F / m and the silica-based fine particles are mixed at a weight ratio of 5: 1 and shaken, whereby the silica-based fine particles are uniformly dispersed in the organic compound; (ii) the silica-based fine particles are dissolved in methanol. After methanol is distilled off from the dispersion dispersed in the evaporator under heating,
When held at a temperature of 100 ° C. for 2 hours, the ratio of the amount of primary particles remaining as primary particles to the amount of primary particles originally present is 20% or more; It is a spherical hydrophobic silica fine particle having a size of 0.01 to 5 μm. The spherical hydrophobic silica fine particles are, for example, SiO ₂
R ² Si0 _3/2 units on the surface of hydrophilic silica fine particles
(Wherein, R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms.) The obtained hydrophobic silica fine particle surface by introducing the R ¹ ₃ Si0 _1/2 units ( However, R ¹ is the same or different and is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 6 carbon atoms.)
An example of a more specific method for producing the spherical hydrophobic silica fine particles is as follows.

A silane compound represented by the general formula (I): Si (OR ³ ) ₄ (where R ³ is the same or different and is a monovalent hydrocarbon group having 1 to 6 carbon atoms) and a partial hydrolyzate thereof. Hydrophilic silica is obtained by hydrolyzing and condensing at least one compound selected from decomposition condensates in a mixed solvent of a hydrophilic solvent such as methanol and ethanol; water and a basic compound such as ammonia and an organic amine. A step of obtaining a fine particle dispersion; adding water to the obtained hydrophilic silica fine particle dispersion, distilling off the hydrophilic solvent to convert the dispersion to an aqueous dispersion,
Completely hydrolyzing the alkoxy group remaining on the surface of the fine particles; adding the aqueous dispersion of hydrophilic silica fine particles thus treated to the aqueous dispersion of the general formula (II): R ² Si (OR ⁴ ) ₃ (where R ² Is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ⁴ is the same or different and has 1 to 6 carbon atoms.
Is a monovalent hydrocarbon group. ) At least one selected from silane compounds and partial hydrolysis condensates thereof
Adding hydrophilic compounds to the surface of hydrophilic silica fine particles to obtain hydrophobic silica fine particles; adding a ketone-based solvent to the hydrophobic silica fine particle aqueous dispersion, and distilling water to remove hydrophobic silica fine particles. step into a ketone solvent dispersion; in and hydrophobic fine silica particles ketone solvent dispersion, the general formula _{^{(III): R 1 3 SiNHSiR}} 1 3 ( where, R ¹ is the same or different substituted or unsubstituted . a monovalent hydrocarbon group having 1 to 6 carbon atoms silazane compound represented by), and the general formula _{^{(IV): R 1 3 SiX}} ( where, R ¹ is the general formula (III) the same .X in OH At least one compound selected from the group consisting of a silane compound represented by formula (1) and a hydrolyzable group), and reacting the silanol group remaining on the surface of the silica fine particles with trialkylsilyl to further highly hydrophobize the silanol group. Obtained by

Specific examples of the tetrafunctional silane compound represented by the general formula (I) include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and tetrabutoxysilane. Specific examples of the partially hydrolyzed condensate of the tetrafunctional silane compound represented by the general formula (I) include methyl silicate and ethyl silicate.

The hydrophilic organic solvent is not particularly limited as long as it dissolves the compound of the formula (I) or its partially hydrolyzed condensate and water. Alcohols, methyl cellosolve, ethyl cellosolve, butyl cellosolve, cellosolve acetate, etc. Cellosolves; ketones such as acetone and methyl ethyl ketone; ethers such as dioxane and tetrahydrofuran; and alcohols are preferable. Examples of the alcohol include an alcohol solvent represented by the general formula (V): R ⁶ OH (V) (where R ⁶ is a monovalent hydrocarbon group having 1 to 6 carbon atoms). As methanol, ethanol, isopropanol,
Butanol and the like. As the number of carbon atoms in the alcohol increases, the particle size of the silica fine particles formed increases. Therefore, it is desirable to select the type of alcohol according to the target particle size of the silica fine particles.

The basic substance includes ammonia, dimethylamine, diethylamine and the like, and is preferably ammonia. After dissolving a required amount of these basic substances in water, the resulting aqueous solution (basic water) may be mixed with a hydrophilic organic solvent.

The amount of water used at this time is represented by the general formula (I)
Is preferably 0.5 to 5 mol with respect to 1 mol of the alkoxy group of the silane compound or its partial hydrolysis condensate, and the ratio of water to the hydrophilic organic solvent is 0.5 to 10 by weight.
The amount of the basic substance is preferably 0.01 to 1 mol based on 1 mol of the alkoxy group of the silane compound of the general formula (I) or the partial hydrolysis condensate thereof.

Hydrolysis and condensation of the tetrafunctional silane compound of the general formula (I) are carried out by mixing a tetrafunctional silane compound of the general formula (I) into a mixed solvent of a hydrophilic organic solvent containing a basic substance and water. Is carried out by a well-known method of dropping water. To convert the dispersion medium of the silica fine particle mixed solvent dispersion into water, for example,
The operation can be performed by adding water to the dispersion and distilling off the hydrophilic organic solvent (this operation is repeated as necessary). The amount of water added at this time is 0.5 to 2 times, preferably almost 1 time, in terms of the weight ratio of the total amount of the used hydrophilic organic solvent and the generated alcohol.

Specific examples of the trifunctional silane compound represented by the general formula (II) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane,
Ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, trifluoro Examples include trialkoxysilanes such as propyltrimethoxysilane and heptadecafluorodecyltrimethoxysilane, and these partially hydrolyzed condensates may be used.

The amount of the trifunctional silane compound represented by the general formula (II) is determined by the amount of SiO _{2 of} the hydrophilic fine silica particles used.
1 to 0.001 mol, preferably 0.1 to 1 mol per unit mol
It is good to use-0.01 equivalent.

In the step of converting the dispersion medium of the aqueous dispersion of hydrophobic silica fine particles into a ketone-based solvent, a ketone-based solvent is added to the dispersion and water is distilled off (this operation is repeated as necessary). Is performed. The amount of the ketone solvent added at this time is 0.5 to 5 times, preferably 1 to 2 times the weight ratio of the hydrophilic silica fine particles used. Specific examples of the ketone solvent used here include methyl ethyl ketone, methyl isobutyl ketone, acetylacetone and the like, and preferably methyl isobutyl ketone.

Specific examples of the silazane compound represented by the general formula (III) include hexamethyldisilazane. Specific examples of the monofunctional silane compound represented by the general formula (IV) include trimethylsilanol and triethyl. Monosilanol compounds such as silanol; monochlorosilane such as trimethylchlorosilane and triethylchlorosilane;
Monoalkoxysilanes such as trimethylmethoxysilane and trimethylethoxysilane; monoaminosilanes such as trimethylsilyldimethylamine and trimethylsilyldiethylamine; and monoacyloxysilanes such as trimethylacetoxysilane.

These are used in an amount of 0.1 to 0.5 mol per mol of SiO ₂ unit of the hydrophilic silica fine particles used,
Preferably, 0.2 to 0.3 mol is used. The spherical hydrophobic silica fine particles thus produced can be obtained as a powder by a conventional method.

Since the spherical hydrophobic silica fine particles of the component (B) are highly hydrophobicized, they are easily dispersed in various organic solvents and organic resins, and adversely affect the slipperiness of the resin surface. Since the given silanol groups hardly exist on the particle surface, good results can be obtained for the objects and effects of the present invention. The particle diameter of the fine particles is O.S. from the viewpoint of the slipperiness of the resin surface, transparency and settling in the uncured resin.
It is necessary that the thickness be 01 to 5 μm, preferably 0.05 to 1 μm. If the particle size is smaller than 0.01 μm, the desired slip property cannot be obtained, and if it exceeds 5 μm, disadvantages such as impaired transparency and easy sedimentation of particles occur.

The amount of the spherical hydrophobic silica fine particles is usually 0.01 to 20 parts by weight based on 100 parts by weight of the polyurethane resin.
It is preferably 0.1 parts by weight, more preferably 0.1 to 5 parts by weight. If the amount is too small, the effect of improving the slipperiness of the resin coat may be difficult to obtain. If the amount is too large, the transparency and strength of the resin coat may be reduced, and it may be economically disadvantageous.

The low-friction treating agent of the present invention comprises the above-mentioned (A) polyurethane resin and (B) spherical hydrophobic silica fine particles and, if necessary, additives such as a smoothness / slipperiness imparting agent and the like as optional components. And prepared by mixing In this case, the polyurethane resin is diluted with an organic solvent or water together with other components at the time of use (at the time of producing a seatbelt), and thus used as a solution dissolved in an organic solvent or a water solvent as described above. Advantageously.

Specific examples of the smoothness / slipperiness imparting agent include:
Examples include mineral oils, animal and vegetable oils, fatty acid esters, alkyl ether esters, modified organosilanes, modified organosiloxanes, and the like. Of these, modified organosilanes and modified organosiloxanes are preferred. As the modified organosilane and the modified organosiloxane,
Modified organosilane and modified organosiloxane such as polyether-modified, fluoroalkyl-modified, and fluoropolyether-modified are mentioned. The amount of the imparting agent is
20 parts by weight or less, preferably 0.01 to 20 parts by weight, is suitable for 100 parts by weight of the polyurethane resin.

<Usage of Low-friction Processing Agent> The low-friction processing agent of the present invention obtained as described above is used for coating a seatbelt webbing to produce a seatbelt. During this treatment, the friction reducing agent is
It may be used as a treatment solution diluted with an organic solvent or water to a concentration of 1 to 20% by weight, or may be used as a stock solution without substantial dilution. The coating method is not particularly limited, and examples thereof include a method of immersing the webbing in a liquid and a method of spraying the liquid on the surface of the webbing. After the coating treatment, the sheet is pre-dried, and is further subjected to a heat treatment at 100 to 180 ° C., thereby obtaining a seat belt with reduced friction. In this case, the amount of the low friction treatment agent attached to the seat belt is O.1 with respect to the total weight of the webbing in the coated portion.
~ 20% by weight is preferred.

The material of the seat belt webbing is not particularly limited, but polyester fiber is particularly effective. If the webbing made of such fiber is coated with the low friction treating agent of the present invention, slipperiness and abrasion resistance are obtained. It is possible to obtain a polyester fiber seat belt which is extremely excellent in both properties and storage properties.

[0035]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the examples, parts represent parts by weight. [Synthesis of spherical hydrophobic silica fine particles] (1) In a 3 liter glass reactor equipped with a stirrer, a dropping funnel and a thermometer, 623.7 g of methanol, 41.4 g of water and 28%
49.8 g of aqueous ammonia was added and mixed. The resulting solution is
Adjust to 5 ° C and, with stirring, tetramethoxysilane 1163.
7 g and 418.1 g of 54% aqueous ammonia were simultaneously added dropwise over 6 hours and 4 hours, respectively. After the dropwise addition of tetramethoxysilane, stirring was continued for 0.5 hour to carry out hydrolysis to obtain a suspension of silica fine particles. Next, an ester adapter and a condenser were attached to the reactor, and heated to 60 to 70 ° C. to distill off 1132 g of methanol. At this time, 1200 g of water was added, and the mixture was further heated to 70 to 90 ° C., and 273 g of methanol was distilled off to obtain an aqueous suspension of silica fine particles. (2) To this aqueous suspension, 11.6 g of methyltrimethoxysilane (equivalent to a molar ratio of 0.01 to tetramethoxysilane) was dropped at room temperature over 0.5 hours while stirring. Even after dripping
Stirring was continued for 12 hours to treat the surface of the silica fine particles. (3) Methyl isobutyl ketone 1 was added to the dispersion thus obtained.
After adding 440 g, heat to 80-110 ° C.
163 g were distilled off over 7 hours. 357.6 g of hexamethyldisilazane was added to the obtained dispersion at room temperature, and the mixture was heated to 120 ° C. and reacted for 3 hours to trimethylsilyl fine silica particles. Thereafter, the solvent is distilled off under reduced pressure to reduce the average particle diameter.
477 g of 0.12 μm spherical hydrophobic silica fine particles were obtained.

Example 1 A 1-liter glass reactor equipped with a stirrer, a dropping funnel and a thermometer was mixed with 31.5 parts of 1,4-butanediol, 200 parts of methyl ethyl ketone and 100 parts of dimethylformamide. Under stirring at 60 ° C, water-added MDI [4,4'-
A mixture of 91 parts of [methylene bis (cyclohexyl isocyanate)] and 190 parts of dimethylformamide was added dropwise over 1 hour, and after completion of the addition, the mixture was reacted at 80 ° C. for 3 hours to obtain 602 parts of a urethane resin solution. The resin content of this solution was 20% by weight. Further, the spherical hydrophobic silica fine particles 5.6 in this solution
Were mixed to obtain a treatment liquid containing a low friction treatment agent. next,
Polyester filament webbing (black dyed product) for automobile seat belts is immersed in this treatment solution, and the friction-reducing agent (the component obtained by removing the solvent from the treatment solution) becomes 0.5% by weight based on the total weight of the webbing. After attaching the treating agent to the webbing, the webbing was preliminarily dried at 110 ° C. for 3 minutes, and then heat-treated at 150 ° C. for 3 minutes. The following evaluation was performed on the seat belt thus manufactured.

<Sliding friction with the through> A load of 500 g is applied to one end of the seat belt, an intermediate portion thereof is inserted through the through, and a load cell of 10 kg at an angle of 20 degrees with the seat belt is inserted into the other end. Load. With this load cell, the strength when raising the load (F1) and the strength when returning the load (F1)
2) Measure and slide the value of [square root of (F2 / F1)] x 100.
(%). The higher the value of the sliding friction, the smaller the frictional resistance with the through and the more excellent the seat belt storage property. As a result, the sliding friction with the through was 61.2%, and the friction characteristics were good.

Comparative Example 1 In place of the spherical hydrophobic silica fine particles of Example 1, Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 20 μm obtained by hydrophobizing fumed silica was used. A processing solution was prepared in the same manner as in Example 1 except for the above. This was attached to the webbing in the same manner as in Example 1, and the obtained seat belt was evaluated. As a result, the sliding friction with the through was 53.1%, and the friction characteristics were insufficient.

Comparative Example 2 Except that the spherical hydrophobic silica fine particles of Example 1 were replaced by Admafine SO-22R (manufactured by Admatech), which is a high-purity spherical amorphous silica having an average particle diameter of 0.3 μm. A treatment liquid was prepared in the same manner as in Example 1. This was attached to the webbing in the same manner as in Example 1, and the obtained seat belt was evaluated. As a result, the sliding friction with the through was 55.6%, and the friction characteristics were insufficient.

[0040]

The low friction treating agent containing the specific spherical hydrophobic silica fine particles of the present invention can be applied to a seat belt webbing to give webbing fibers, especially polyester webbing fibers, a sufficiently high initial slip property. That is, since excellent frictional characteristics are imparted, there is no deterioration in characteristics such as slipperiness and abrasion resistance over time and no adhesion of dirt. Therefore, the seat belt coated with the friction reducing agent of the present invention does not have the resin on the belt surface scraped off over a long period of use, unlike a conventional seat belt whose surface is simply coated with resin alone, In addition, there is no decrease in the storage property due to the adhesion of the scraped resin or dirt.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) C08L 75/04 C08L 75/04 C09D 5/00 C09D 5/00 G 175/04 175/04 183/04 183/04 C10M 107/44 C10M 107/44 125/26 125/26 D06M 11/79 D06M 15/564 15/564 23/10 23/10 D06M 11/12 // C10N 40:32

Claims (2)

[Claims] (A) a polyurethane resin, and (B) an organic compound and a silica which are liquid at room temperature and have a dielectric constant of 1 to 40 F / m, under the following conditions (i) and (ii): When the silica-based particles are mixed and shaken at a weight ratio of 5: 1, the silica-based particles are uniformly dispersed in the organic compound; (ii) methanol is dispersed from a dispersion in which the silica-based particles are dispersed in methanol. Is distilled off under heating with an evaporator,
When held at a temperature of 100 ° C. for 2 hours, the ratio of the amount of primary particles remaining as primary particles to the amount of primary particles originally present is 20% or more; The friction reducing agent for a seat belt according to claim 1, comprising a polyurethane resin composition containing spherical hydrophobic silica fine particles having a particle size of 0.01 to 5 µm. 2. The method according to claim 1, wherein the hydrophobic silica fine particles of the component (B) are
iO_TwoR on the surface of hydrophilic silica fine particles^TwoSiO_3/2single
Position (however, R^TwoIs substituted or unsubstituted monovalent having 1 to 20 carbon atoms
It is a hydrocarbon group. )
R on the surface of hydrophobic silica fine particles ¹ _ThreeSi0_1/2Unit (however, R¹Is
Same or different substituted or unsubstituted C 1 -C 1
Is a multivalent hydrocarbon group. )
The sheet according to claim 1, which is a hydrophobic silica fine particle.
Low friction treating agent for belts.