JP2009167255A - Low-combustible flexible polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-combustible flexible polyurethane foam capable of well maintaining physical properties of a flexible polyurethane foam, and exhibiting low combustibility without using a flame retardant. <P>SOLUTION: The low-combustible flexible polyurethane foam is obtained by reacting and foaming a foam raw material comprising polyols, polyisocyanates, a blowing agent, and a catalyst. The polyols or the polyisocyanates are formed by using a vegetable-derived raw material. The ratio of the vegetable-derived raw material is set at 15-75 mass% based on the raw material for the foam. At least one of a vegetable-derived polyol obtained by carrying out a condensation reaction of a polyol having a plurality of hydroxy groups with a vegetable-derived higher fatty acid as the polyols and a vegetable-derived polyisocyanate prepolymer prepared by reacting a polyisocyanate with a vegetable-derived polyol and having an isocyanate group at the terminal as the polyisocyanates is preferably used. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a low-flammability soft polyurethane foam for imparting low-flammability (flame retardancy) to products such as electronic parts and automobile parts.

  Conventionally, halogens, metal oxides, and the like have been added to impart low flammability to polyurethane foam, which is a material for electronic parts and automobile parts. In particular, when halogen is used, low flammability can be easily imparted to the polyurethane foam. In order to impart low flammability without using halogen, low flammability can be imparted by using a metal oxide or a phosphoric acid-based flame retardant. On the other hand, carbon dioxide emission regulations have been enacted in recent years, and the raw materials are in an environment where they are shifted from fossil fuels to biomass raw materials, and in particular, product development using plant-derived raw materials is being promoted rapidly.

  For example, the present applicant has proposed a non-halogen type low-flammability polyurethane foam that does not use halogen (see, for example, Patent Document 1). That is, the low-flammability polyurethane foam is obtained by reacting a polyol and a polyisocyanate in the presence of a flame retardant, a catalyst, and a foaming agent. The polyol contains a phthalate ester polyol, and the flame retardant has an average particle size. It contains melamine powder with a diameter of 0.5 μm or less.

Further, a polyurethane foam in which at least a part of a polyol derived from petroleum is replaced with an alkoxylated vegetable oil hydroxylate is known (see, for example, Patent Document 2). That is, the polyurethane foam contains a reaction product obtained by reacting at least one alkoxylated vegetable oil hydroxylate containing 15 to 90% by mass of alkoxylate based on polyisocyanate and alkoxylated vegetable oil hydroxylate. Specifically, a polyurethane foam using soybean oil polyol as a polyol is disclosed.
JP 2007-2036 A (2nd and 4th pages) JP 2006-291205 A (page 2, page 18 and page 19)

  However, in the low-flammability polyurethane foam described in Patent Document 1, the blending amount of the melamine powder must be increased in order to increase the low-flammability. In that case, the physical properties of the polyurethane foam due to excess melamine powder There was a problem that the effect on the water was large and the balance with low flammability was lacking. On the other hand, the polyurethane foam described in Patent Document 2 is intended to obtain a polyurethane foam manufactured with an environmentally friendly and reproducible component. Therefore, the polyurethane foam is environmentally friendly and has relatively good physical properties. The body is obtained. However, since the proportion of the plant-derived component in the foam raw material is small in order to maintain good physical properties, there is a problem that low combustibility is insufficient.

  Accordingly, an object of the present invention is to provide a low-flammability soft polyurethane foam that can maintain good physical properties of the soft polyurethane foam and can exhibit excellent low-flammability. .

  In order to achieve the above object, the low combustible flexible polyurethane foam according to claim 1 is obtained by reacting and foaming a foam raw material containing polyols, polyisocyanates, a foaming agent and a catalyst. And polyols or polyisocyanate is formed using the raw material derived from a plant, The ratio of the raw material derived from the plant is 15-75 mass% with respect to a foam raw material, It is characterized by the above-mentioned.

  In the low combustible flexible polyurethane foam of Claim 2, in the invention which concerns on Claim 1, the plant-derived polyol formed by condensation-reacting the polyol which has a some hydroxyl group, and the plant-derived higher fatty acid as said polyol, and poly Polyisocyanate and the plant-derived polyol are reacted as isocyanates, and at least one of plant-derived polyisocyanate prepolymers having an isocyanate group at the terminal is used.

According to a third aspect of the invention, in the invention according to the second aspect, the plant-derived higher fatty acid is a compound having 12 to 18 carbon atoms.
In the low-flammability soft polyurethane foam of Claim 4, in the invention which concerns on Claim 2 or Claim 3, the said plant origin derived from the condensation reaction of the polyol which has a some hydroxyl group, and the higher fatty acid derived from a plant as said polyols A polyisocyanate and a plant-derived polyisocyanate prepolymer having an isocyanate group at the terminal are used by reacting a polyisocyanate with the plant-derived polyol as a polyisocyanate.

According to the present invention, the following effects can be exhibited.
In the low-flammability flexible polyurethane foam according to claim 1, polyols or polyisocyanates are formed using plant-derived raw materials, and the proportion of the plant-derived raw materials is 15 to 75% by mass with respect to the foam raw materials. It is. The plant-derived raw materials that form polyols or polyisocyanates have a large proportion of hydrocarbon chains that do not have oxygen atoms, and therefore can impart low combustibility to flexible polyurethane foams. For this reason, low flammability can be expressed even if a flame retardant is not blended, and physical properties of the flexible polyurethane foam due to excessive blending of the flame retardant can be avoided. Furthermore, the balance between low combustibility and physical properties can be achieved by using plant-derived raw materials as the polyols or polyisocyanates in an amount of 15 to 75% by mass based on the foam raw material. Therefore, the physical properties of the flexible polyurethane foam can be maintained well and excellent low combustibility can be exhibited.

  In the low-flammability soft polyurethane foam according to claim 2, a plant-derived polyol obtained by a condensation reaction of a polyol having a plurality of hydroxyl groups and a higher fatty acid derived from a plant as a polyol, and a polyisocyanate derived from the plant as a polyisocyanate. At least one of a plant-derived polyisocyanate prepolymer having an isocyanate group at the terminal by reacting with a polyol is used. For this reason, the effect of the invention which concerns on Claim 1 can be show | played by the raw material derived from at least one of polyols and polyisocyanate.

  In the low-flammability soft polyurethane foam according to claim 3, the plant-derived higher fatty acid is a compound having 12 to 18 carbon atoms. For this reason, in addition to the effect of the invention according to claim 2, the low flammability of the flexible polyurethane foam can be effectively exhibited without hindering the urethanization reaction.

  In the low-flammability soft polyurethane foam according to claim 4, a plant-derived polyol obtained by condensation reaction of a polyol having a plurality of hydroxyl groups and a plant-derived higher fatty acid is used as the polyol, and the polyisocyanate and the polyisocyanate are used as the polyisocyanate. A plant-derived polyisocyanate prepolymer having an isocyanate group at the terminal is used by reacting with a plant-derived polyol. For this reason, in addition to the effect of the invention which concerns on Claim 2 or Claim 3, the low combustibility of a flexible polyurethane foam can be exhibited most effectively.

In the following, embodiments that are considered to be the best of the present invention will be described in detail.
The low-flammability soft polyurethane foam of the present embodiment (hereinafter, also simply referred to as a soft polyurethane foam, polyurethane foam or foam) reacts with a foam raw material containing polyols, polyisocyanates, a foaming agent and a catalyst. And foamed. The polyols or polyisocyanates are formed using plant-derived raw materials, and the ratio of the plant-derived raw materials is set to 15 to 75 mass%, preferably 25 to 75 mass% with respect to the foam raw material. . By setting the ratio of the plant-derived raw material within this range, the low combustibility and good physical properties of the flexible polyurethane foam can be exhibited in a well-balanced manner.

  When the proportion of the plant-derived raw material is less than 15% by mass, the desired low combustibility cannot be imparted to the flexible polyurethane foam. On the other hand, when it is more than 75% by mass, the urethanization reaction and the foaming reaction are hindered, and the physical properties of the obtained flexible polyurethane foam are deteriorated. Such low-flammability soft polyurethane foams are suitably used in fields such as electronic parts such as buffer materials for printers and automobile interior parts such as pads, which require environmental performance and low-flammability.

  The flexible polyurethane foam is formed by reacting and foaming a foam raw material containing polyols, polyisocyanates, a foaming agent and a catalyst. Here, the flexible polyurethane foam is lightweight, generally has an open cell structure in which cells communicate, is flexible, and has resilience. Below, a foam raw material is demonstrated in order.

  First, as the polyols, plant-derived polyols are used. Since such a plant-derived polyol is a polyol having a large proportion of hydrocarbon chains not containing oxygen atoms, it can exhibit low combustibility. These plant-derived polyols are compounds obtained by a condensation reaction of a polyol having a plurality of hydroxyl groups [a polyol derived from fossil fuel (non-vegetable oil)] and a plant-derived higher fatty acid. Examples of the polyol having a plurality of hydroxyl groups include polyols such as ethylene glycol, glycerin, and trimethylolpropane, and polyols obtained by adding an alkylene oxide such as ethylene oxide and propylene oxide to the polyol. As plant-derived higher fatty acids, lauric acid (carbon number 12), myristic acid (carbon number 14), palmitic acid (carbon number 16), stearic acid (carbon number 18), capric acid (carbon number 10), caprylic acid (Carbon number 8) etc. are used. In addition, said carbon number shows carbon number of the fatty acid used as the central component, since it is a mixture of what a plant-derived higher fatty acid differs in carbon number.

  The plant-derived higher fatty acid is preferably a compound having 12 to 18 carbon atoms. When the carbon number is within this range, the hydrocarbon chain not containing oxygen atoms is sufficiently contained, and the foam can exhibit good low combustibility. When the number of carbon atoms is less than 12, the foam cannot exhibit sufficient low combustibility and is inferior in hydrolyzability. On the other hand, when the number of carbon atoms exceeds 18, the reactivity of the urethanization reaction is lowered, which is not preferable as a foam material.

  Specific examples of plant-derived polyols include castor oil polyol, soybean oil polyol, palm oil polyol, palm kernel oil polyol, coconut oil polyol, olive oil polyol, cottonseed oil polyol, safflower oil polyol, sesame oil polyol, sunflower oil polyol, and linseed oil polyol. Etc. These plant-derived polyols usually have 2 to 3 functional groups of hydroxyl groups in one molecule.

  As the polyols, in addition to plant-derived polyols, polyether polyols, polyester polyols or polyether polyester polyols generally used as foam raw materials are used. As polyether polyol, the compound which added alkylene oxides, such as propylene oxide and ethylene oxide, to polyols, such as ethylene glycol, glycerol, and sorbitol, is mentioned, for example.

  As polyester polyols, in addition to condensation polyester polyols obtained by reacting polycarboxylic acids such as adipic acid and phthalic acid with polyols such as ethylene glycol, diethylene glycol, propylene glycol and glycerin, lactone polyester polyols and polycarbonate systems A polyol is mentioned.

  Examples of the polyether polyester polyol include those obtained by reacting a polycarboxylic acid such as adipic acid or phthalic acid with a compound obtained by adding an alkylene oxide such as propylene oxide or ethylene oxide to a polyol such as ethylene glycol, glycerin, or sorbitol. Used. These polyols can change the number of hydroxyl groups and the hydroxyl value by adjusting the kind of raw material components, the molecular weight, the degree of condensation, and the like.

  Moreover, a crosslinking agent can be mix | blended as some polyols. Examples of the crosslinking agent include polyols (polyfunctional alcohols) such as polyethylene glycol, diethylene glycol, polypropylene glycol, glycerin, trimethylolpropane, pentaerythritol, and sorbitol, or compounds obtained by extending the polyol with an alkylene oxide or the like. . By containing a crosslinking agent, the crosslink density of a flexible polyurethane foam can be raised and the mechanical physical property of a foam can be improved.

  Next, the polyisocyanate to be reacted with polyols is a compound having a plurality of isocyanate groups, and a prepolymer having an isocyanate group at the terminal obtained by reacting polyisocyanate (derived from fossil fuel) and the plant-derived polyol ( Plant-derived polyisocyanate prepolymers). As the polyisocyanate, those generally used as a foam raw material are used, and the plant-derived polyol described above is used as the plant-derived polyol. In this case, polyisocyanate is used in excess of the plant-derived polyol, and the reaction is carried out so that isocyanate groups remain at the ends. For example, a plant-derived polyisocyanate prepolymer having an isocyanate group at the end is prepared by heating and reacting castor oil polyol and tolylene diisocyanate for a predetermined time so that the tolylene diisocyanate is in excess of the castor oil polyol. Can do.

  As the polyisocyanate, polyisocyanate (polyisocyanate derived from fossil fuel) generally used as a foam raw material is used in addition to the plant-derived polyisocyanate prepolymer having an isocyanate group at the terminal. Such polyisocyanates include tolylene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate, xylylene diisocyanate (XDI), hexamethylene diisocyanate ( HDI), dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI) and the like. Among these, tolylene diisocyanate is preferable for producing a polyurethane foam having a low density (light specific gravity).

  The isocyanate index (isocyanate index) of the polyisocyanates is appropriately set, but is preferably set to 70 to 130, more preferably 100 to 120. By setting the isocyanate index to 100 to 120, the crosslink density of the foam can be increased, and the physical properties such as mechanical properties of the foam can be increased, and a good foam can be obtained.

  Here, the isocyanate index represents the equivalent ratio of the isocyanate group of the polyisocyanate to the active hydrogen group such as the hydroxyl group of the polyol, the hydroxyl group of the polyol as the crosslinking agent, and the foaming agent (water) in percentage. An isocyanate index exceeding 100 means that the isocyanate group is in excess of the active hydrogen group. When the isocyanate index is less than 70, the reaction of polyisocyanates with polyols and the like is insufficient, the foam tends to burst and collapse, and the crosslinking density of the resulting foam is lowered, so that the foam is soft. As a result, the mechanical properties deteriorate. On the other hand, when the isocyanate index exceeds 130, the crosslink density of the foam is increased, the connectivity of the cell is deteriorated, and the strain (strain) characteristic tends to be lowered.

  The low flammability soft polyurethane foam is obtained by using at least one of the aforementioned plant-derived polyol and plant-derived polyisocyanate prepolymer. In order to most effectively exhibit the low flammability of the foam, it is desirable to use a plant-derived polyol and a plant-derived polyisocyanate prepolymer in combination. In general, plant-derived polyols are easy to use because they are readily available, but plant-derived polyisocyanate prepolymers also react easily by mixing plant-derived polyols with polyisocyanates and heating them. Can be used.

  Subsequently, the catalyst is for accelerating a resinification reaction (urethanization reaction) between polyols and polyisocyanates, and for promoting a foaming reaction between polyisocyanates and water as a blowing agent. In particular, a metal catalyst is used as a catalyst for selectively promoting the resinification reaction, and an amine catalyst is particularly used as a catalyst for promoting the foaming reaction. Specifically, tin such as tin octylate (tin octoate), dibutyltin dilaurate, tin dibutyldiacetate, tin di (2-ethylhexyl) dilaurate, di (2-ethylhexanoate) tin, dioctyltin dilaurate Examples thereof include compounds and di (2-ethylhexanoic acid) lead. Specific examples of the amine catalyst include tertiary amines such as N, N ′, N′-trimethylaminoethylpiperazine, triethylenediamine, and dimethylethanolamine.

  The content of the metal catalyst is preferably 0.05 to 2.5 parts by mass per 100 parts by mass of polyols. When the content of the metal catalyst is less than 0.05 parts by mass, the progress of the resinification reaction is insufficient, the foam tends to rupture and collapse, the crosslink density of the resulting foam decreases, and the mechanical properties are reduced. Damaged. On the other hand, when the amount is more than 2.5 parts by mass, the resinification reaction proceeds excessively, the foam has a high crosslinking density, the cell membrane increases, the cell connectivity is inhibited, and the air permeability deteriorates. . Moreover, it is preferable that content of an amine catalyst is 0.1-7.0 mass parts per 100 mass parts of polyols. When the content of the amine catalyst is less than 0.1 parts by mass, the foaming reaction is not sufficiently progressed, and the connectivity of the cells of the resulting foam is lowered and the air permeability tends to be impaired. On the other hand, when the amount is more than 7.0 parts by mass, the progress of the foaming reaction becomes excessive, and the reaction adjustment becomes difficult, so that it is difficult to ensure productivity. Moreover, the balance between foaming and resinification cannot be achieved, and it becomes difficult to obtain a good foam. In addition, the catalyst is used in combination with an amine catalyst and a metal catalyst, or an amine catalyst used alone or appropriately adjusted.

  Next, the foaming agent is for foaming polyurethane into a polyurethane foam. Examples of the foaming agent include water commonly used in the production of flexible polyurethane foam (reacts with polyisocyanates to generate carbon dioxide gas), water and halogenated aliphatic hydrocarbons as auxiliary foaming agents, such as The combined use with methylene chloride, trichloroethane, carbon dioxide, etc., and the combined use with acid amide are preferred. Among these foaming agents, water having excellent foaming reaction reactivity and good handleability is preferred, but when seeking a lightweight foam, not only water, but also a halogenated hydrocarbon that is an auxiliary foaming agent, The combined use with carbon dioxide gas or the like is preferable.

  In the case of water, the foaming agent content is preferably 1.5 to 5.0 parts by mass per 100 parts by mass of polyols. When the content of the foaming agent is less than 1.5 parts by mass, the foaming reaction becomes insufficient and the foam cannot be obtained in a stable state. On the other hand, when the content of the foaming agent is more than 5.0 parts by mass, there is a problem of heat generation due to the reaction between water and polyisocyanates, or the open cell structure of the foam is not sufficiently formed, which is not preferable. . Although content of an auxiliary | assistant foaming agent is suitably determined in order to adjust the apparent density of a foam, it is preferable that it is 1.0-10 mass parts per 100 mass parts of polyols. When the content of the auxiliary foaming agent is less than 1.0 part by mass, the amount of vaporization of the auxiliary foaming agent is small, and the effect as the auxiliary foaming agent tends to decrease. On the other hand, when the amount is more than 10 parts by mass, sufficient vaporization due to heat generation is not performed, and a satisfactory effect as an auxiliary foaming agent cannot be obtained.

  Subsequently, the foam stabilizer is used as necessary in order to smoothly advance foaming performed by the foaming agent. As such a foam stabilizer, what is normally used when manufacturing a flexible polyurethane foam can be used. Specific examples of the foam stabilizer include silicone compounds, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, polyether siloxane, and phenolic compounds. The content of the foam stabilizer is set according to a conventional method. In addition to the above-mentioned raw materials, flame retardants, antioxidants, ultraviolet absorbers, colorants, foam breakers (fillers) and the like can be blended in the foam raw material according to a conventional method.

  The aforementioned reaction between the polyols and the polyisocyanates is carried out according to a conventional method, and a one-shot method or a prepolymer method is employed. The one-shot method is a method in which polyols and polyisocyanates are directly reacted. The prepolymer method is a method in which a part of a polyol and a polyisocyanate are reacted in advance to obtain a prepolymer having an isocyanate group or a hydroxyl group at a terminal, and the polyol or the polyisocyanate is reacted therewith. Moreover, as a soft polyurethane foam, the soft slab polyurethane foam obtained by a slab foaming method is preferable. In the slab foaming method, the reaction raw material (reaction mixture) mixed and stirred by the one-shot method is discharged onto a belt conveyor, and the reaction raw material reacts at normal temperature and atmospheric pressure while the belt conveyor moves. Obtained by foaming. Thereafter, it is cured (cured) in a drying furnace and cut into a predetermined shape. In addition, a flexible polyurethane foam can also be obtained by a molding method, an on-site spray molding method, or the like.

The soft polyurethane foam thus obtained has an apparent density of 15 to 150 kg / m ³ , preferably 20 to 80 kg / m ³ . Here, the apparent density is a value measured according to JIS K 7222: 1999. When this apparent density is lower than 15 kg / m ³ , the proportion of cells in the foam increases and the resin skeleton tends to decrease, and the foam tends to become brittle, which is not preferable as a flexible polyurethane foam. On the other hand, when the apparent density is higher than 150 kg / m ³ , there are few physical demerits, but it is difficult to obtain a great merit that it can be designed to be lightweight.

  Since the ratio of the plant-derived raw material is set to 15 to 75% by mass with respect to the foam raw material and the soft polyurethane foam exhibits good low flammability, at least the US safety standard UL94-HF2 regarding low flammability. Can be met. Furthermore, low combustibility is further improved by setting the proportion of plant-derived raw material to 25 to 75 mass% with respect to the foam raw material, and the US safety standard UL94-HF1 can be satisfied with respect to low combustibility.

  Further, regarding the physical properties of the foam, the tensile strength is preferably 50 to 230 kPa, the elongation is preferably 100 to 180%, and the hardness is preferably 2 to 10 kPa, which is good as a flexible polyurethane foam. Can exhibit excellent physical properties.

The actions and effects exhibited by the above embodiment will be described collectively below.
-In the flexible polyurethane foam of this embodiment, polyols or polyisocyanates are formed using plant-derived raw materials, and the proportion of the plant-derived raw materials is set to 15 to 75 mass% with respect to the foam raw materials. The Since the plant-derived raw material that forms polyols or polyisocyanates is composed of hydrocarbon chains that do not have oxygen atoms, the supply of oxygen is suppressed, and the flammability of the foam can be suppressed.

  For this reason, even if it does not mix | blend a flame retardant, a foam can express low combustibility and can avoid the physical-property fall of the foam by the excessive mixing | blending of a flame retardant. Furthermore, a good foam can be obtained by using 15 to 75% by mass of a plant-derived raw material as a polyol or polyisocyanate with respect to the foam raw material, and the balance between the low flammability and the mechanical properties of the foam. Can be achieved. Accordingly, it is possible to obtain an environmentally friendly foam, maintain good physical properties of the foam, and exhibit excellent low flammability without using a flame retardant.

  -By using at least one of the aforementioned plant-derived polyol and the plant-derived polyisocyanate prepolymer having an isocyanate group as a terminal as the polyol, the above-described effects are exhibited by at least one plant-derived raw material of the polyols and polyisocyanates. be able to.

-Since the higher fatty acid derived from a plant is a compound having 12 to 18 carbon atoms, the low flammability of the foam can be effectively exhibited without hindering the urethanization reaction.
-By using a plant-derived polyol as the polyol and a plant-derived polyisocyanate prepolymer as the polyisocyanate, the low flammability of the foam can be exhibited most effectively.

Hereinafter, the embodiment will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the scope of these examples.
(Examples 1-12 and Comparative Examples 1-3)
A foam raw material of a flexible polyurethane foam containing polyols, polyisocyanates, foaming agent, foam stabilizer and catalyst was prepared with the composition shown in Table 1. The numerical value of the foam raw material in Table 1 represents part by mass. Then, by mixing the foam raw material at room temperature and reacting and foaming (slab foaming) according to a conventional method, a flexible polyurethane foam (block body) having a length of about 400 mm, a width of 400 mm and a thickness of about 300 mm is produced. The measurement was evaluated by cutting the block body.

The foam raw material shown in Table 1 will be described below.
Castor oil polyol: hydroxyl value 160 mgKOH / g, number of functional groups of hydroxyl group in one molecule 2.7, manufactured by Ito Oil Co., Ltd., URIC H-30
Soybean oil polyol 1: hydroxyl value 52 mgKOH / g, number of hydroxyl functional groups in one molecule 2.0, manufactured by USSC, Soyol R2-052 G
Soybean oil polyol 2: hydroxyl value 170 mgKOH / g, number of hydroxyl functional groups in one molecule 3.0, manufactured by USSC, Soyol R3-170 G
Palm oil polyol: hydroxyl value 154 mgKOH / g, manufactured by Sanyo Chemical Industries, Imex-Polygreen61
Fossil fuel polyol 1: hydroxyl value 35 mgKOH / g, number of hydroxyl functional groups in one molecule 3.0, manufactured by Sanyo Chemical Industries, FA703
Fossil fuel polyol 2: hydroxyl value 56 mgKOH / g, manufactured by Sanyo Chemical Industries, Ltd., # 3000 (A-12)
Fossil fuel polyol 3: hydroxyl value 60.5 mgKOH / g, polyol having 2.7 functional groups of hydroxyl groups in one molecule, adipic acid (6 carbon atoms) added to trimethylolpropane and diethylene glycol, Nippon Polyurethane Industry Co., Ltd. N-2200
Polyisocyanate prepolymer 1: a reaction product of 53% by weight of castor oil polyol (manufactured by Ito Oil Co., Ltd., URIC H-30) and 47% by weight of tolylene diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate T-65) Polyisocyanate prepolymer having an isocyanate group at the terminal, isocyanate group content 16% by mass
Polyisocyanate prepolymer 2: Reaction product of castor oil polyol (made by Ito Oil Co., Ltd., URIC H-30) 63 mass% and tolylene diisocyanate (produced by Nippon Polyurethane Industry Co., Ltd., Coronate T-65) 37 mass% Polyisocyanate prepolymer having an isocyanate group at the terminal, isocyanate group content 10% by mass
In addition, polyisocyanate prepolymers 1 and 2 are prepared by adding a predetermined amount of castor oil polyol and tolylene diisocyanate to a reaction vessel, heating to 70 to 80 ° C. with stirring, and maintaining the temperature for 3 hours and 30 minutes. And then cooled to room temperature.

Polyisocyanate prepolymer 3: a polyisocyanate prepolymer having an isocyanate group at the terminal and a reaction product of castor oil polyol and 4,4-diphenylmethane diisocyanate (MDI), an isocyanate group content of 16% by mass, and an isocyanate group in one molecule Functional group number 2.0, Ito Oil Co., Ltd., URIC N-2023
Polyisocyanate T-65: a mixture of 65% by mass of 2,4-tolylene diisocyanate and 35% by mass of 2,6-tolylene diisocyanate, an isocyanate group content of 48% by mass, and the number of functional groups of isocyanate groups in one molecule. 0, manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate T-65
Polyisocyanate T-80: A mixture of 80% by mass of 2,4-tolylene diisocyanate and 20% by mass of 2,6-tolylene diisocyanate, an isocyanate group content of 48% by mass, and the number of functional groups of isocyanate groups in one molecule. 0, manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate T-80
Amine catalyst 1: Triethylenediamine: dipropylene glycol = 33: 67 (mass ratio) catalyst Amine catalyst 2: Kao Corporation No. 3
Amine catalyst 3: Kao Corporation No. 8
Metal catalyst 1: Tin octylate, manufactured by Johoku Chemical Industry Co., Ltd., MRH-110
Metal catalyst 2: dibutyltin dilaurate, manufactured by Kyodo Pharmaceutical Co., Ltd., KS-1260
Foam stabilizer 1: Silicone foam stabilizer, manufactured by Toray Dow Silicone Co., Ltd., PRX607
Foam stabilizer 2: Silicone foam stabilizer, manufactured by Toray Dow Silicone Co., Ltd., SZ-1336
Foam stabilizer 3: Silicone foam stabilizer, manufactured by Toray Dow Silicone Co., Ltd., SZ-1720
Foam stabilizer 4: Silicone foam stabilizer, manufactured by Toray Dow Silicone Co., Ltd., SH-192
Flame retardant: Phosphate ester, manufactured by Daihachi Chemical Co., Ltd., SH-880
Plant ratio (%) indicating the ratio of plant-derived raw materials:
(Mass of plant-derived material / mass of foam material) × 100
And about the obtained flexible polyurethane foam, while measuring an apparent density, tensile strength, elongation, and hardness by the method shown below, the combustibility test was done according to the following method. The results are shown in Table 1.

Apparent density (kg / m ³ ): Measured according to JIS K 7222 (1999).
Tensile strength (kPa): measured in accordance with JIS K 6400-5 (2004).
Elongation (%): Measured according to JIS K 6400-5 (2004).

Hardness (25% compression, kPa): Measured according to JIS K 6400-2 (2004).
Flammability test: A foam sample having a thickness of 3 mm was measured in accordance with US safety standards UL94-HF1 and UL94-HF2.

  Here, in Comparative Examples 1-3, the example in case the ratio of the plant-derived raw material is less than 15 mass% with respect to a foam raw material is shown.

表１に示した結果より、実施例１〜１２では植物由来の原料の割合が発泡体原料に対して１５．３〜７２．１質量％に設定されていることから、発泡体の引張強さ、伸び、硬さなどの物性を良好に発揮することができると共に、燃焼性試験において少なくとも米国安全規格ＵＬ９４−ＨＦ２に合格する性能を発揮することができた。特に、ポリオール類とポリイソシアネート類の双方に植物由来の原料を用い、植物比率の高い実施例４〜７及び実施例９、１０の場合には、燃焼距離が短く、米国安全規格ＵＬ９４−ＨＦ１に合格する結果が得られた。

From the result shown in Table 1, in Examples 1-12, since the ratio of the plant-derived raw material is set to 15.3-72.1 mass% with respect to the foam raw material, the tensile strength of a foam In addition to being able to exhibit excellent physical properties such as elongation and hardness, it was possible to exhibit at least performance that passed the US safety standard UL94-HF2 in the flammability test. In particular, in the case of Examples 4 to 7 and Examples 9 and 10 in which plant-derived raw materials are used for both polyols and polyisocyanates and the plant ratio is high, the combustion distance is short, and the US safety standard UL94-HF1 is satisfied. A passing result was obtained.

On the other hand, in Comparative Example 1, since the ratio of the plant-derived raw material was set to less than 15% by mass with respect to the foam raw material, the foam failed the US safety standard UL94-HF2 in the flammability test. . Furthermore, in Comparative Examples 2 and 3, since the ratio of the plant-derived raw material was smaller than that of Comparative Example 1 and the isocyanate index was high, the foam raw material was not balanced and foaming could not be performed.
(Examples 13 to 23 and Comparative Example 4)
The composition of the foam raw material was set as shown in Table 2, and the same operation as in Example 1 was performed to prepare a flexible polyurethane foam. About the obtained flexible polyurethane foam, while measuring an apparent density, tensile strength, elongation, and hardness, the combustibility test was measured. The results are shown in Table 2.

表２に示した結果より、実施例１３〜２３では植物由来の原料の割合を発泡体原料に対して２０．９〜４８．７質量％に設定したことから、発泡体の引張強さ、伸び、硬さなどの物性を良好に発揮することができると共に、燃焼試験において少なくとも米国安全規格ＵＬ９４−ＨＦ２に合格する性能を発揮することができた。特に、ポリオール類とポリイソシアネート類の双方に植物由来の原料を用い、植物比率の高い実施例１３〜１５及び実施例１８〜２３の場合には、燃焼距離が短く、米国安全規格ＵＬ９４−ＨＦ１に合格する結果が得られた。また、実施例１８〜２２ではイソシアネート指数を７０〜１３０まで変化させたが、優れた低燃焼性と良好な機械的物性を発揮することができた。なお、実施例１８には難燃剤が含まれていることから、低燃焼性が非常に優れていた。

From the result shown in Table 2, in Examples 13-23, since the ratio of the raw material derived from a plant was set to 20.9-48.7 mass% with respect to the foam raw material, the tensile strength and elongation of the foam In addition to being able to exhibit excellent physical properties such as hardness, it was possible to exhibit at least performance that passed the US safety standard UL94-HF2 in the combustion test. In particular, in the case of Examples 13 to 15 and Examples 18 to 23 where plant-derived raw materials are used for both polyols and polyisocyanates and the plant ratio is high, the combustion distance is short, and the US safety standard UL94-HF1 is satisfied. A passing result was obtained. Moreover, in Examples 18-22, although the isocyanate index was changed from 70-130, the outstanding low combustibility and the favorable mechanical physical property were able to be exhibited. In addition, since the flame retardant was contained in Example 18, low combustibility was very excellent.

On the other hand, in the comparative example 4, since the raw material derived from a plant was not contained in the foam raw material, it was a result of failing the US safety standard UL94-HF2 in the flammability test for the foam.
In addition, this embodiment can also be changed and embodied as follows.

-As a vegetable oil polyol, corn oil polyol, koji oil polyol, olive oil polyol, tung oil polyol, etc. can be used.
-It is also possible to use vegetable oil polyol in combination with beef tallow polyol, lard tallow polyol, sardine oil polyol, mackerel oil polyol and the like as animal oil polyol.

A plurality of plant-derived polyisocyanate prepolymers having different isocyanate group contents using plant-derived raw materials can also be used as polyisocyanates.
Further, the technical idea that can be grasped from the embodiment will be described below.

  The ratio of the plant-derived raw material is 25 to 75% by mass with respect to the foam raw material, and the low-flammability flexible polyurethane foam according to any one of claims 1 to 4. When comprised in this way, the effect of the invention which concerns on any one of Claims 1-4 can be improved further.

  The low-flammability soft polyurethane according to any one of claims 2 to 4, wherein the polyisocyanate forming the plant-derived polyisocyanate prepolymer having an isocyanate group at the terminal is tolylene diisocyanate. Foam. When comprised in this way, in addition to the effect of the invention which concerns on any one of Claims 2-4, a flexible polyurethane foam can be easily made into a low density.

Claims (4)

A flexible polyurethane foam obtained by reacting and foaming a foam raw material containing a polyol, a polyisocyanate, a foaming agent and a catalyst,
The polyol or polyisocyanate is formed using a plant-derived raw material, and the proportion of the plant-derived raw material is 15 to 75% by mass with respect to the foam raw material, and is a low-flammability flexible polyurethane foam body. A plant-derived polyol obtained by condensation reaction of a polyol having a plurality of hydroxyl groups and a plant-derived higher fatty acid as the polyol, and a polyisocyanate having an isocyanate group at the terminal by reacting the polyisocyanate with the plant-derived polyol as the polyisocyanate. The low-flammability soft polyurethane foam according to claim 1, wherein at least one of plant-derived polyisocyanate prepolymers is used. The low-combustible soft polyurethane foam according to claim 2, wherein the plant-derived higher fatty acid is a compound having 12 to 18 carbon atoms. A plant-derived polyol obtained by condensation reaction of a polyol having a plurality of hydroxyl groups and a plant-derived higher fatty acid is used as the polyol, and a polyisocyanate is reacted with the plant-derived polyol as a polyisocyanate to form an isocyanate group at the terminal. The low-combustible soft polyurethane foam according to claim 2 or 3, wherein a plant-derived polyisocyanate prepolymer having odor is used.