JP7844883B2 - Polyol composition - Google Patents

Description

This invention relates to a polyol composition containing vinyl chloride-based crosslinked copolymer particles, and more particularly to a polyol composition comprising vinyl chloride-based crosslinked copolymer particles dispersed therein that exhibit excellent storage stability and dispersion stability, good handling performance, and are suitable as a polyurethane forming material.

Conventionally, methods for flame-retardantizing polyurethane have been proposed using polyols containing polyvinyl chloride particles as raw materials. For example, these include polyol dispersions containing 1-50 μm polyvinyl chloride particles (see, for example, Patent Document 1), methods using polyvinyl chloride particles and a carbonyl group-containing compound as a stabilizer (see, for example, Patent Document 2), and methods for preparing polyols by polymerizing vinyl chloride monomers in a polyol to disperse polyvinyl chloride particles (see, for example, Patent Document 3).

Furthermore, to improve dispersion stability, vinyl chloride polymer latex containing vinyl chloride polymer, phosphate ester, or phosphate ester salt with a volume-average particle size of 0.2 to 2 μm has been proposed (see, for example, Patent Document 4).

Japanese Patent Application Publication No. 01-065160 Japanese Patent Application Publication No. 09-059341 Japanese Patent Application Publication No. 03-097715 Japanese Patent Publication No. 2016-029140

However, the proposals in Patent Documents 1 to 3 had problems with the dispersibility and stability of polyvinyl chloride particles in polyols. Furthermore, the vinyl chloride polymer latex proposed in Patent Document 4 concerns latex itself, which has excellent dispersion stability, and does not address dispersion stability in polyol compositions.

Therefore, there is a need for a polyol composition that exhibits excellent storage stability and dispersion stability of polyvinyl chloride particles.

As a result of diligent research into the above-mentioned problems, the inventors of this invention discovered that a polyol composition comprising vinyl chloride copolymer particles having a cross-linked structure dispersed in a polyol exhibits excellent storage stability and dispersion stability, making it suitable as a polyurethane raw material. This led to the completion of the present invention.

In other words, the present invention relates to a polyol composition characterized by dispersing vinyl chloride copolymer particles having a crosslinked structure, containing 0.1 to 1.0% by weight of polyfunctional monomer residue units having two or more ethylenically double bonds in the molecule and an average particle size of 0.1 to 1.5 μm, in a polyol, and having a solid content concentration of 10 to 45% by weight.

The present invention will be described in detail below.

The polyol composition of the present invention comprises a polyol in which vinyl chloride copolymer particles having a crosslinked structure with an average particle diameter of 0.1 to 1.5 μm are dispersed as solid content. These crosslinked vinyl chloride copolymer particles contain 0.1 to 1.0% by weight of polyfunctional monomer residue units having two or more ethylenically double bonds within the molecule.

The polyols constituting the polyol composition of the present invention may be any polyol belonging to the category known as polyols. Examples include conventionally known polyether polyols, polyester polyols, polymer polyols, polycarbonate polyols, and flame-retardant polyols such as phosphorus-containing polyols and halogen-containing polyols. These polyols can be used individually or mixed and used in combination as appropriate.

Polyether polyols are not particularly limited, and examples include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, and pentaerythritol, which are compounds having at least two active hydrogen groups; amines such as ethylenediamine; and alkanolamines such as ethanolamine and diethanolamine, etc., which are produced by addition reactions of these starting materials with alkylene oxides such as ethylene oxide and propylene oxide (see, for example, Gunter Oertel, "Polyurethane Handbook" (1985), Hanser Publishing GmbH (Germany), pp. 42-53).

Polyester polyols are not particularly limited; examples include those obtained from the reaction of dibasic acids and glycols, waste materials from nylon manufacturing, trimethylolpropane, pentaerythritol waste, phthalate polyester waste, and polyester polyols derived from processed waste materials (see, for example, Keiji Iwata, "Polyurethane Resin Handbook" (1987), Nikkan Kogyo Shimbun, p. 117).

The polymer polyol is not particularly limited, and examples include polymer polyols obtained by reacting the aforementioned polyether polyol with ethylenically unsaturated monomers such as butadiene, acrylonitrile, and styrene in the presence of a radical polymerization catalyst.

Flame-retardant polyols are not particularly limited and include, for example, phosphorus-containing polyols obtained by adding alkylene oxides to phosphoric acid compounds, halogen-containing polyols and phenolic polyols obtained by ring-opening polymerization of epichlorohydrin or trichlorobutylene oxide.

Examples of commercially available polyols include (trade name) Sannix (manufactured by Sanyo Chemical Industries, Ltd.), (trade name) Exenol (manufactured by Asahi Glass Co., Ltd.), (trade name) Actcol (manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), and (trade name) Voranol (manufactured by DOW Corporation).

Furthermore, among these polyols, polyols with an average hydroxyl value in the range of 20 to 1000 mgKOH/g are preferred. In particular, when constituting raw materials for the production of flexible polyurethanes or semi-rigid polyurethanes, polyols with an average hydroxyl value in the range of 20 to 100 mgKOH/g are preferred, and when constituting raw materials for the production of rigid polyurethanes, polyols with an average hydroxyl value in the range of 100 to 800 mgKOH/g are preferred.

The vinyl chloride crosslinked copolymer particles constituting the polyol composition of the present invention are vinyl chloride copolymers having a crosslinked structure derived from polyfunctional monomer residue units having two or more ethylenically double bonds in the molecule, and any such copolymer may be used. By including vinyl chloride crosslinked copolymer particles as solid content in the polyol, a polyol composition is obtained that has excellent affinity with the polyol, excellent dispersibility and storage stability, and also possesses reactivity. If vinyl chloride polymer particles without a crosslinked structure are used, the resulting polyol composition will have poor dispersibility when the vinyl chloride polymer particles are concentrated at high concentrations. The content of polyfunctional monomer residue units having two or more ethylenically double bonds in the vinyl chloride crosslinked copolymer particles is preferably 0.1 to 1.0 wt%, and is particularly excellent in dispersibility, storage stability, and reactivity. Therefore, it is preferable that the content of polyfunctional monomer residue units having two or more ethylenically double bonds in the molecule is 0.1 to 0.8 wt%. Here, if the concentration is less than 0.1 wt%, the resulting vinyl chloride copolymer particles will not exhibit the effects of the crosslinked structure when used in a polyol composition, resulting in poor dispersibility at high concentrations. On the other hand, if the concentration of vinyl chloride crosslinked copolymer particles exceeds 1.0 wt%, the reaction system becomes unstable during production, making it difficult to stably produce the particles.

Furthermore, the vinyl chloride-based crosslinked copolymer particles have an average particle diameter of 0.1 to 1.5 μm, and since this results in extremely excellent mechanical strength, a diameter of 0.2 to 1.2 μm is preferable. If the average particle diameter is less than 0.1 μm, the viscosity of the polyol composition increases, resulting in poor fluidity and processability. On the other hand, if the average particle diameter exceeds 1.5 μm, the polyol composition suffers from poor dispersibility and storage stability. Regarding the method for measuring the average particle diameter, for example, a method of measuring the particle diameter distribution using a disk centrifugal particle size distribution analyzer and determining the average particle diameter can be used.

Furthermore, the vinyl chloride-based crosslinked copolymer particles can be prepared, for example, by copolymerizing a vinyl chloride-based monomer with a polyfunctional monomer having two or more ethylenically coupled double bonds in its molecule. The amount of polyfunctional monomer having two or more ethylenically coupled double bonds in its molecule should be such that vinyl chloride-based crosslinked copolymer particles with a polyfunctional monomer residue unit content of 0.1 to 1.0 wt% can be efficiently produced, and is preferably 0.1 to 1.0 wt%, with a particularly good dispersibility, storage stability, and reactivity, therefore preferably 0.1 to 0.8 wt. In this case, vinyl chloride monomers include not only vinyl chloride monomers but also copolymerizable monomers. Examples of polyfunctional monomers having two or more ethylenic double bonds in their molecules include triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, ethylene glycol divinyl ether, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diallyl phthalate, vinyl methacrylate, and vinyl crotate. These can be used individually or in combination of two or more.

As a method for producing the vinyl chloride crosslinked copolymer particles, any method that enables the production of the vinyl chloride crosslinked copolymer particles may be used. For example, a method of producing a vinyl chloride copolymer having a crosslinked structure by copolymerization of a vinyl chloride monomer with a polyfunctional monomer having two or more ethylenically double bonds in its molecule can be used. When producing the vinyl chloride crosslinked copolymer particles, polymerization initiators, emulsifiers, chain transfer agents, buffers, water-soluble initiators, reducing agents, etc., can be used as appropriate. These additives may, insofar as they achieve the objectives of the present invention, be included in the vinyl chloride crosslinked copolymer particles as solid components.

The polymerization initiator used in this process can be any substance belonging to the category of polymerization initiators. Examples include water-soluble polymerization initiators such as potassium persulfate and ammonium persulfate; and oil-soluble polymerization initiators such as azo compounds like azobisisobutyronitrile, and peroxides such as lauroyl peroxide, t-butyl peroxypivalate, diacyl peroxide, peroxyesters, and peroxydicaponate. Furthermore, when performing seed micro-suspension polymerization, seed particles (seeds) containing oil-soluble initiators may also be used.

Examples of emulsifiers include general anionic or nonionic emulsifiers. Anionic emulsifiers include alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate; alkyl sulfate esters such as sodium lauryl sulfate and sodium tetradecyl sulfate; sulfosuccinates such as sodium dioctyl sulfosuccinate and sodium dihexyl sulfosuccinate; fatty acid salts such as sodium laurate and potassium semi-hardened beef tallow fatty acid; ethoxysulfate salts such as sodium polyoxyethylene lauryl ether sulfate and sodium polyoxyethylene nonylphenyl ether sulfate; alkanesulfonates; and sodium alkyl ether phosphate esters. Nonionic emulsifiers include, for example, polyoxyethylene nonylphenyl ether and polyoxyethylene sorbitan lauryl ester. Among these, it is preferable to use alkylbenzene sulfonates, alkyl sulfate esters, or mixtures of alkylbenzene sulfonates and alkyl sulfate esters, as this enables more stable production of vinyl chloride crosslinked copolymer particles. Furthermore, regarding the timing of adding the emulsifier, it is sufficient that the emulsifier is present during homogenization. It may be added entirely before or during homogenization, or a portion may be added before or during homogenization, with the remaining emulsifier being added intermittently or continuously during polymerization.

Furthermore, examples of polymerization methods in this manufacturing method include: a microsuspension polymerization method in which vinyl chloride monomer, a polyfunctional monomer having two or more ethylenically double bonds in its molecule, an emulsifier, an oil-soluble polymerization initiator, and, if necessary, an emulsifying aid such as an aliphatic higher alcohol are added to deionized water, mixed and dispersed using a homogenizer, and then polymerized under gentle stirring; a seed microsuspension polymerization method using seed particles (seeds) containing an oil-soluble polymerization initiator obtained by the microsuspension polymerization method; and a seed emulsion polymerization method in which particles obtained by emulsion polymerization, in which vinyl chloride monomer is polymerized with deionized water, an emulsifier, and a water-soluble polymerization initiator under gentle stirring, are used as seeds for emulsion polymerization. In these cases, for example, the polymerization temperature is set to 30 to 80°C, and the latex containing dispersed vinyl chloride crosslinked copolymer particles can be obtained.

Furthermore, the latex can be obtained as primary particles or aggregates thereof by spray drying. The aggregates can also be obtained as vinyl chloride crosslinked copolymer particles by grinding as needed. The dryer used to obtain the vinyl chloride crosslinked copolymer particles can be a commonly used type, such as a spray dryer (a specific example is the various spray dryers described in Figure 4.10 on page 121 of "SPRAY DRYING HANDBOOK" (by K. Masters, 3rd edition, 1979, published by George Godwin Limited)). There are no particular restrictions on the drying air inlet temperature and drying air outlet temperature; generally, a drying air inlet temperature of 80 to 200°C and a drying air outlet temperature of 45 to 75°C are used, with a drying air inlet temperature of 100 to 170°C and a drying air outlet temperature of 50 to 70°C being more preferable. The vinyl chloride crosslinked copolymer particles obtained after drying are primary particles or aggregates of latex, and are preferably in the form of granules of 10 to 100 μm. If the drying outlet temperature exceeds 55°C, it is preferable to pulverize the obtained vinyl chloride crosslinked copolymer for better dispersion in the polyol composition. If the drying outlet temperature is 55°C or lower, it may be used in granular form or pulverized. Furthermore, if the vinyl chloride crosslinked copolymer particles obtained by spray drying or the like are aggregates of primary particles, it is preferable that they disperse in the polyol and disperse as primary particles in the polyol composition.

The polyol composition of the present invention exhibits excellent workability and dispersibility, and therefore, a viscosity of 10,000 mPa·s or less, particularly 1,000 to 9,500 mPa·s, and more preferably 1,000 to 8,000 mPa·s, is preferable.

The method for producing the polyol composition of the present invention may be any method that enables the production of the polyol composition. Examples include mixing the vinyl chloride crosslinked copolymer particles with the polyol, mixing a latex containing vinyl chloride crosslinked copolymer particles with the polyol, and then dehydrating the resulting mixture.

The polyol composition of the present invention can be used as a raw material for polyurethanes, particularly flame-retardant polyurethanes, due to its excellent dispersibility, storage stability, and reactivity. For example, by incorporating isocyanate compounds such as aromatic polyisocyanates (e.g., toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthylene diisocyanate, xylylene diisocyanate), aliphatic polyisocyanates (e.g., hexamethylene diisocyanate), alicyclic polyisocyanates (e.g., dicyclohexyl diisocyanate, isophorone diisocyanate), or mixtures thereof, and/or other polyisocyanate compounds, it can be used as a polyurethane-forming composition or polyurethane.

The polyol composition of the present invention exhibits excellent storage stability and dispersion stability, as well as good handling, making it suitable as a polyurethane forming material.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples.

<Method for measuring the average particle size of vinyl chloride crosslinked copolymer particles>
The particle size distribution of vinyl chloride crosslinked copolymer particles was measured using a disk centrifugal particle size distribution analyzer (CPS Instruments, product name: CPS Disc Centrifuge) under conditions of a refractive index of 1.4, and the average particle size was determined.

<Measuring viscosity>
Viscosity was measured using a Type B viscometer in accordance with JIS K-1557-5.

<Storage Stability Test>
The storage stability test involved placing the polyol composition in a transparent glass bottle, leaving it at room temperature for one month, and visually inspecting for the presence or absence of sediment in the polyol composition.

Synthesis Example 1
300 kg of deionized water, 300 kg of vinyl chloride monomer, 5.3 kg of lauroyl peroxide, and 18 kg of 25% by weight sodium dodecylbenzenesulfonate aqueous solution were charged into a ¹ m³ stainless steel autoclave. The mixture was homogenized by circulating it in a homogenizer for 3 hours, and then the temperature of the reaction system was raised to 45°C to start polymerization. After the pressure in the polymerization system decreased, the unreacted vinyl chloride monomer was recovered, and seed latex a was obtained with a solid content of 35% by weight, an average particle size of 0.55 μm, and containing 2% by weight of lauroyl peroxide as the polymer base.

Synthesis Example 2
350 kg of deionized water, 300 kg of vinyl chloride monomer, 81 g of potassium persulfate, 10 kg of 16% by weight potassium laurate aqueous solution, and 20 kg of 25% by weight sodium dodecylbenzenesulfonate aqueous solution were charged into a ¹ m³ stainless steel autoclave. The temperature of the reaction system was then raised to 54°C to start polymerization. After the pressure in the polymerization system decreased, the unreacted vinyl chloride monomer was recovered to obtain seed latex b with a solid content of 40% by weight and an average particle size of 0.15 μm.

Example 1
In a 2.5 L stainless steel autoclave, 840 g of deionized water, 720 g of vinyl chloride monomer, 1.15 g of diallyl phthalate, 8.6 g of 5% by weight sodium dodecylbenzenesulfonate, 4.2 parts by weight of seed latex a obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 1.5 parts by weight of seed latex b obtained in Synthesis Example 2 per 100 parts by weight of vinyl chloride monomer were charged. The temperature of this reaction mixture was raised to 45°C and polymerization was started. From the start to the end of polymerization, 0.703 parts by weight of 5% by weight sodium dodecylbenzenesulfonate was continuously added to the vinyl chloride monomer. Polymerization was stopped when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 45°C to 0.461 MPa, and the unreacted vinyl chloride monomer and diallyl phthalate were recovered to obtain a latex containing vinyl chloride crosslinked copolymer particles.

The obtained vinyl chloride crosslinked copolymer particles had an average primary particle size of 1.23 μm, and the content of diallyl phthalate residue units, calculated from unreacted vinyl chloride monomer and diallyl phthalate, was 0.16% by weight. The latex was then spray-dried using a spray dryer at a hot air inlet temperature of 158°C and an outlet temperature of 55°C to obtain aggregates of vinyl chloride crosslinked copolymer particles.

350 g of the obtained vinyl chloride-based crosslinked copolymer particle aggregate and 650 g of glycerin-based polyether polyol ((trade name) Exenol EL-820, manufactured by AGC, OH value: 33 KOH/g) were kneaded in a dissolver mixer to obtain a creamy polyol composition with a solid content of 35% by weight.

The resulting polyol composition contained dispersed vinyl chloride-based crosslinked copolymer particles with an average particle size of 1.23 μm, and its viscosity was 4100 mPa·s. A one-month storage stability test revealed no particle sedimentation, indicating a uniform state.

Example 2
200 g of the vinyl chloride-based crosslinked copolymer particle aggregate obtained in Example 1 and 800 g of glycerin-based polyether polyol ((trade name) Exenol EL-820, manufactured by AGC, OH value: 33 KOH/g) were kneaded in a dissolver mixer to obtain a creamy polyol composition with a solid content of 20% by weight.

The resulting polyol composition contained dispersed vinyl chloride-based crosslinked copolymer particles with an average particle size of 1.23 μm, and its viscosity was 2200 mPa·s. A one-month storage stability test revealed no particle sedimentation, indicating a uniform state.

Example 3
In a 2.5 L stainless steel autoclave, 600 g of deionized water, 800 g of vinyl chloride monomer, 4.0 g of triallyl isocyanurate, 8.6 g of 5% by weight sodium dodecylbenzenesulfonate, 4.5 parts by weight of seed latex a obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 3.0 parts by weight of seed latex b obtained in Synthesis Example 2 per 100 parts by weight of vinyl chloride monomer were charged. The temperature of this reaction mixture was raised to 48°C to start polymerization. From the start to the end of polymerization, 0.703 parts by weight of 5% by weight sodium dodecylbenzenesulfonate was continuously added to the vinyl chloride monomer. Polymerization was stopped when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 48°C to 0.402 MPa, and the unreacted vinyl chloride monomer and triallyl isocyanurate were recovered to obtain latex of vinyl chloride copolymer particles having a crosslinked structure.

The obtained vinyl chloride crosslinked copolymer particles had an average primary particle size of 1.20 μm, and the content of triallyl isocyanerate residue units, calculated from unreacted vinyl chloride monomer and triallyl isocyanurate, was 0.5% by weight. The latex was then spray-dried using a spray dryer at a hot air inlet temperature of 158°C and an outlet temperature of 55°C to obtain aggregates of vinyl chloride crosslinked copolymer particles.

350 g of the obtained vinyl chloride-based crosslinked copolymer particle aggregate and 650 g of glycerin-based polyether polyol ((trade name) Exenol EL-820, manufactured by AGC, OH value: 33 KOH/g) were kneaded in a dissolver mixer to obtain a creamy polyol composition with a solid content of 35% by weight.

The resulting polyol composition contained dispersed vinyl chloride-based crosslinked copolymer particles with an average particle size of 1.20 μm, and its viscosity was 3500 mPa·s. A one-month storage stability test revealed no particle sedimentation, indicating a uniform state.

Example 4
In a 2.5 L stainless steel autoclave, 600 g of deionized water, 800 g of vinyl chloride monomer, 4.0 g of triallyl isocyanurate, 8.6 g of 5% by weight sodium dodecylbenzenesulfonate, and 4.5 parts by weight of seed latex a obtained in Synthesis Example 1 were charged per 100 parts by weight of vinyl chloride monomer. The temperature of this reaction mixture was raised to 48°C to start polymerization. From the start to the end of polymerization, 0.703 parts by weight of 5% by weight sodium dodecylbenzenesulfonate was continuously added to the vinyl chloride monomer. Polymerization was stopped when the polymerization pressure dropped from the saturated vapor pressure of vinyl chloride monomer at 48°C to 0.402 MPa, and the unreacted vinyl chloride monomer and triallyl isocyanurate were recovered to obtain latex of vinyl chloride-based crosslinked copolymer particles.

The obtained vinyl chloride crosslinked copolymer particles had an average primary particle size of 1.30 μm, and the content of triallyl isocyanerate residue units, calculated from unreacted vinyl chloride monomer and triallyl isocyanurate, was 0.5% by weight. The latex was then spray-dried using a spray dryer at a hot air inlet temperature of 158°C and an outlet temperature of 55°C to obtain aggregates of vinyl chloride crosslinked copolymer particles.

350 g of the obtained vinyl chloride-based crosslinked copolymer particle aggregate and 650 g of glycerin-based polyether polyol ((trade name) Exenol EL-820, manufactured by AGC, OH value: 33 KOH/g) were kneaded in a dissolver mixer to obtain a creamy polyol composition with a solid content of 35% by weight.

The resulting polyol composition contained dispersed vinyl chloride-based crosslinked copolymer particles with an average particle size of 1.30 μm, and its viscosity was 5600 mPa·s. A one-month storage stability test revealed no particle sedimentation, indicating a uniform state.

Comparative Example 1
In a 2.5 L stainless steel autoclave, 840 g of deionized water, 720 g of vinyl chloride monomer, 10.8 g of diallyl phthalate, 8.6 g of 5% by weight sodium dodecylbenzenesulfonate, 4.2 parts by weight of seed latex a obtained in Synthesis Example 1 per 100 parts by weight of vinyl chloride monomer, and 1.5 parts by weight of seed latex b obtained in Synthesis Example 2 per 100 parts by weight of vinyl chloride monomer were charged. The temperature of this reaction mixture was raised to 45°C to attempt the production of vinyl chloride copolymer particles with a triallyl isocyanerate residue unit content of 1.5% by weight.

However, the reaction system became unstable during the polymerization reaction, making it impossible to obtain latex with normal vinyl chloride copolymer particles.

Comparative Example 2
50 g of the vinyl chloride-based crosslinked copolymer particle aggregate obtained in Example 1 and 950 g of glycerin-based polyether polyol ((trade name) Exenol EL-820, manufactured by AGC, OH value: 33 KOH/g) were kneaded in a dissolver mixer to obtain a creamy polyol composition with a solid content of 5% by weight.

The obtained polyol composition contained dispersed vinyl chloride-based crosslinked copolymer particles with an average particle size of 1.23 μm, and its viscosity was 1000 mPa·s. A one-month storage stability test revealed particle sedimentation, indicating poor stability.

Comparative Example 3
500 g of the vinyl chloride-based crosslinked copolymer particle aggregate obtained in Example 1 and 500 g of glycerin-based polyether polyol ((trade name) Exenol EL-820, manufactured by AGC, OH value: 33 KOH/g) were kneaded in a dissolver mixer to obtain a creamy polyol composition with a solid content of 50% by weight.

The resulting polyol composition contained dispersed vinyl chloride-based crosslinked copolymer particles with an average particle size of 1.23 μm. Its viscosity was high at 12,300 mPa·s, presenting challenges in processability.

The polyol composition of the present invention exhibits low sedimentation, excellent storage stability and dispersion stability, and good handling performance. Furthermore, because the polyol composition of the present invention can produce polyurethane resins with good dispersion stability, it is expected to be suitable for use in the polyurethane resin manufacturing industry.

Claims (3)

A polyol composition characterized by dispersing vinyl chloride copolymer particles having a crosslinked structure, containing 0.1 to 1.0% by weight of polyfunctional monomer residue units having two or more ethylenically double bonds in the molecule and an average particle size of 0.1 to 1.5 μm, in a polyol, with a solid content concentration of 10 to 45% by weight. The polyol composition according to claim 1, characterized in that its viscosity is 10,000 mPa·s or less. The polyol composition according to claim 1 or 2, characterized in that the polyfunctional monomer residue units having two or more ethylenically double bonds in the molecule are triallyl isocyanurate residue units and/or diallyl phthalate residue units.