JPS6123931B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyurethane containing a siliceous filler, and more particularly to a method for producing polyurethane containing a siliceous filler that improves elongation at break. Polyurethane is a polymer having urethane bonds, and is mainly obtained by condensation of isocyanate groups and active hydrogen groups. In the following, the polyurethane-forming raw material mainly refers to an isocyanate compound having at least two isocyanate groups and an active hydrogen compound having at least two active hydrogens, the details of which will be described later. Polyurethanes obtained from polyurethane-forming raw materials are used in a variety of applications, particularly in foams and elastomers. Others: paints, adhesives, fibers,
It is also used in artificial leather, caulking materials, thermoplastic resins, thermosetting resins, etc. Among these, polyurethane used in molded products such as foams, elastomers, and thermoplastic resins is sometimes filled with silicic acid fillers. Although the polyurethane filled with a silicic acid filler is not limited to polyurethane used as a molded article, below, foams and elastomers filled with a silicic acid filler will be mainly described. A silicic acid filler is a filler containing silicic acid, and includes, for example, fibrous fillers such as glass fiber, asbestos, and calcium silicate (wollastonite), glass flakes, and flat plates such as natural mica and synthetic mica. filler, glass powder, silica,
Powder to granular fillers such as talc, clay, glass beads, and silica balloons are available. Among these, fibrous fillers and flat fillers are particularly effective in improving the physical properties of synthetic resins, particularly in improving the strength and modulus of elasticity, and are used as reinforcing fillers for synthetic resins. Powder to granular fillers are mainly used as fillers, but they also have the effect of reinforcing synthetic resins. When polyurethane is filled with the above filler,
The strength and modulus of elasticity are improved, and this effect is particularly noticeable when filled with fibrous fillers or flat fillers. However, on the other hand, there is a problem in that the elongation at break of polyurethane decreases when the siliceous filler is filled. For example, in the case of a polyurethane elastomer alone, the elongation rate up to breakage is large in a tensile strength test, whereas the rate of elongation up to breakage is small in a polyurethane elastomer filled with a silicic acid filler. This is equivalent to a decrease in the physical properties of the elastomer.
Therefore, in the case of polyurethane elastomers, it is often desired that they be filled with silicic acid fillers to improve their strength and elastic modulus while at the same time minimizing the decrease in elongation at break. Similarly, even in foams with high elongation such as flexible polyurethane foams, it is considered preferable that the elongation at break is less reduced by filling with a silicic acid filler. Reaction injection molding is a method that simultaneously manufactures and molds polyurethane.
Molding) is attracting attention. This is a molding method in which at least two components, a liquid component containing an isocyanate compound and a liquid component containing an active hydrogen compound, are mixed immediately before a mold, immediately injected into the mold, and the mixture is reacted and cured in the mold to obtain a polyurethane molded product. It is. This method has many advantages, such as the injection of liquid components, which requires low injection pressure, the need to heat and melt the resin, which requires less thermal energy, and the ability to directly obtain molded products from polyurethane forming raw materials. This is a unique molding method, and it is expected that this method will become widely used in the future. A method of molding filler-containing polyurethane using this reaction injection molding (hereinafter referred to as RIM) method has been studied. In particular, the greatest challenge is to obtain fiber-reinforced polyurethane molded products using milled glass fibers, chopped strands, or silicic acid fillers such as wollastonite as fillers. Regarding the RIM method for fiber-reinforced polyurethane, some proposals have already been made regarding the equipment and method, and the length and diameter of the glass fibers used for this purpose, as well as the amount of filling thereof, etc., are also being studied. However, in polyurethanes containing silicic acid fillers produced by the RIM method, the problem of the decrease in elongation at break has not yet been sufficiently studied, and no solution to the problem has yet been proposed. The present inventor molded polyurethane containing a silicic acid filler such as milled glass fiber by the RIM method or a method equivalent thereto,
In addition to measuring its tensile strength and elastic modulus, we also measured the percentage of elongation at break. Using this method, we conducted various research studies in order to find a polyurethane containing silicic acid fillers that exhibits less reduction in elongation at break. I went.
In order to improve the physical properties of synthetic resins containing general fillers, there are methods of surface treatment of fillers and methods of adding additives to synthetic resins. The inventor mainly
We searched for compounds that can be used for surface treatment of fillers. However, it is generally also effective as a surface treatment agent or additive. When used as an additive, there is a problem that the amount used is generally larger than when used as a surface treatment agent.
It has the characteristic of being easy to use because it does not require any surface treatment procedure and can be simply added to the raw materials. In the present invention, since a relatively expensive compound is used as explained below, it is preferable to use it as a surface treatment agent. In addition, the method using the compound described below is not limited to the case of molding polyurethane by the RIM method, but it involves reacting polyurethane-forming raw materials in the presence of a silicic acid filler to form a polyurethane containing a silicic acid filler. It is also considered to be effective in manufacturing. The present inventor conducted research and examination on various compounds in order to find a surface treatment agent or additive that can improve the elongation at break of polyurethane containing silicic acid fillers. It has been found that acrylic ester or methacrylic ester of alcohol is effective. The present invention is a process for producing polyurethanes containing this treated siliceous filler and a process for producing polyurethanes containing siliceous fillers not treated with this compound and this compound added as an additive. That is, the present invention is directed to "reacting an isocyanate compound having at least two isocyanate groups with an active hydrogen compound having at least two active hydrogens in the presence of a siliceous filler to produce a siliceous filler-containing product". A method for producing a polyurethane containing a silicic acid filler, characterized in that a fluorine-based surfactant or an acrylic ester or methacrylic ester of a long-chain alkyl alcohol is present together with the silicic acid filler. method”. The improvement in elongation at break, which is the object of the present invention, means that the rate at which the elongation of polyurethane decreases due to the addition of a siliceous filler is small. The elongation of polyurethane containing no siliceous filler is high, but the elongation decreases as the amount of siliceous filler increases. The rate of elongation is measured by subjecting a test piece to a tensile test and determining the ratio of the length at which the test piece breaks to the original length of the test piece. This elongation at break is not proportional to the tensile strength. for example,
Even if the tensile strength is high, the elongation at break is low. Generally, when filled with fibrous fillers such as glass fibers, the tensile strength of polyurethane is greatly improved, but the elongation at break often decreases.
If this elongation at break is improved, the tensile strength generally tends to decrease. An object of the present invention is to improve the elongation at break without significantly inhibiting the improvement in physical properties such as tensile strength due to the addition of a silicic acid filler. The fluorine-based surfactant is a surfactant containing a fluorine atom in its constituent components, and a surfactant containing a polyfluoroalkyl group is particularly preferred. The polyfluoroalkyl group-containing fluorine-containing surfactant is not particularly limited, and a wide variety of conventionally known and well-known surfactants can be employed, for example. The polyfluoroalkyl group preferably has 4 to 20 carbon atoms, and is usually preferably a perfluoroalkyl group, and has 6 to 20 carbon atoms.
Preferably 18 pieces. Of course, the polyfluoroalkyl group may be linear or branched, and may contain partial hydrogen atoms, chlorine atoms, etc., or may contain an ether bond. As the polyfluoroalkyl group, one in which at least the terminal end is a perfluoroalkyl group is preferably selected. A wide variety of types of fluorine-based surfactants can be employed, including anionic, cationic, nonionic, and amphoteric surfactants. Among these fluorine-containing surfactants, particularly preferred are fluorine-containing double surfactants and fluorine-containing cationic surfactants. Examples of fluorine-based surfactants include the general formula

Examples include betaine type amphoteric surfactants represented by the formula: In the formula, R _f
is a polyfluoroalkyl group having 4 to 20 carbon atoms, particularly a perfluoroalkyl group having 6 to 18 carbon atoms, and W is a divalent organic bonding group, preferably -
It is QR-. Q is −CON(R ¹ )− or −SO ₂ N
(R ¹ )-, where R ¹ is a hydrogen atom or has 1 to 4 carbon atoms
R is a divalent alkylene group having 1 to 10 carbon atoms. R ² and R ³ are an alkyl group, a hydroxyalkyl group, or -ACOOM, and in some cases may be -WR _f , and R ² and R ³ may be the same or different groups. A has 1 carbon number
~3 divalent alkylene groups, M is an alkali metal such as sodium, potassium, or _-NH4 .
Z is an anionic group such as -ACOO or _-ASO3 . Specific compounds thereof are described, for example, in US Pat. No. 3,836,552, Japanese Patent Publication No. 48-23161, US Pat. In addition, polyfluoroalkyl group-containing amphoteric surfactants and glycine-type fluorine-based amphoteric surfactants such as those described in JP-A-48-44182 and JP-A-51-125213 are also used. obtain. Furthermore, fluorine-based amphoteric surfactants containing a piperazine ring as described in Japanese Patent Application No. 128717-1982 and polyfluoroalkyl group-containing amphoteric surfactants as described in Japanese Patent Application No. 53-55530. An activator or the like may also be used. Examples of fluorine-based cationic surfactants include:
general formula

Examples include quaternary ammonium salts of the formula. In the above formula, R _f is a polyfluoroalkyl group having 4 to 20 carbon atoms, particularly a perfluoroalkyl group having 6 to 18 carbon atoms, and Q is -CON
(R ¹ )- or -SO ₂ N(R ¹ )-, R ¹ is a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms, and R is a divalent alkylene group having 1 to 10 carbon atoms. be. or,
R ⁴ , R ⁵ , R ⁶ are hydrogen atoms, alkyl groups, hydroxyalkyl groups, or -ACOOM, A is a divalent alkylene group having 1 to 3 carbon atoms, M is an alkali metal such as sodium or potassium, or _−NH4 . X is a halogen atom, -HSO ₄ , -CH ₃ SO ₄ , -
_{H2PO4 , -CH3COO} or _-CH2ClCOO .
In addition, R may be linear or branched, and R ⁴ ,
One of R ⁵ and R ⁶ , R ¹ and R may form a ring. In addition, in the present invention, U.S. Patent No.
4062849, U.S. Patent No. 4049668,
Fluorine surfactants such as perfluoropolycationic surfactants as described in JP-A No. 50-83306, JP-A No. 51-42086, JP-A-50-30608, etc. are also used. It is possible. Other compounds used in this invention are acrylic or methacrylic esters of long chain alkyl alcohols. Long-chain alkyl alcohol is an alcohol having an alkyl group having 8 or more carbon atoms, especially a long-chain alkyl group, and has the general formula C _o H ₂
It is represented by _o+1 OH (n: 8 or more).
The carbon number n of the alkyl group is preferably 10 to 20. Specific long-chain alkyl alcohols include:
Examples include n-dodecyl alcohol, n-tetrazyl alcohol, cetyl alcohol, and stearyl alcohol. The desired acrylic ester or methacrylic ester can be obtained by reacting these long-chain alkyl alcohols with acrylic acid or methacrylic acid, or by other methods. In the following explanation, when the above compound is used as a surface treatment agent for a siliceous filler, it is referred to as a treatment agent, and when it is included in polyurethane without pre-treating the siliceous filler, it is referred to as an additive. Make it. The processing agent containing the above compound is usually used in the form of a solution or dispersion. The type of solvent or dispersion medium is not particularly limited. For example, water, lower alcohols, lower halogenated hydrocarbons, ethers, ketones, and other liquid materials that can dissolve or disperse the above compounds are suitable. The solvent or dispersion medium may be one type or a mixture of two or more types.
Furthermore, the processing agent containing at least one of the compounds according to the present invention may further contain other additives. Examples include PH regulators, viscosity regulators, surfactants, dispersion stabilizers, lubricants, antistatic agents, antifoaming agents, fine particle powders, etc. Furthermore, in addition to the above-mentioned compounds, organic silicon compounds and synthetic resins such as epoxy resins may be added. The concentration of the compound of the present invention in the treatment agent is not particularly limited. This is because when the concentration is low, the treatment with the treatment agent can be repeated. However, if the concentration is too high, the amount of adhesion to the filler will be too large, and the effect will not improve commensurately, so there will be limitations. The concentration of the above compounds in the treatment agent is usually 0.001~
It is preferably about 10% by weight, particularly 0.1 to 5.0% by weight. The treatment method using the treatment agent is not particularly limited. For example, the treatment agent is brought into contact with the filler using various methods, such as impregnating the filler with the treatment agent, spraying the treatment agent onto the filler, mixing the treatment agent and the filler and then separating them. A common method is to remove the solvent or dispersion in the agent by evaporation. Furthermore, when the filler is glass fiber or the like, it can be directly treated with a treatment agent during the manufacturing process. In the case of glass fiber milled fibers or chopped strands, the rovings treated with a treatment agent can be cut to obtain the treated milled fibers or chopped strands. The amount of the above-mentioned compound in the present invention attached to the treated filler is not particularly limited as long as it is attached to the extent that the effect of the treatment can be exhibited.
However, if the filler is glass fiber, for example,
0.01 to 0.5% by weight is appropriate, so generally
It is thought that the effect is exhibited at about 0.001 to 5.0% by weight. On the other hand, the above-mentioned compound in the present invention may be added as an additive to the polyurethane forming raw material without being supported on the siliceous filler. The amount of this additive added is the amount that can exhibit the effect of its addition,
The amount is not particularly limited as long as it does not inhibit the molding of polyurethane. However, the usual usage amount is 10% by weight or less, especially 0.005% by weight based on the silicic acid filler.
~5% by weight is suitable. That is, when the amount of siliceous filler in the molded product is 20% by weight, the amount of additives contained in the molded product is 2% by weight or less, especially
0.1 to 1% by weight is suitable. The effect of improving the elongation at break is, but is not limited to, 1.5 times or more of the elongation when no additive is included.
In particular, it is preferable that the elongation is twice or more. The additive is added to the polyurethane before the reaction of the polyurethane-forming raw material mixture is completed, that is, before the polyurethane-forming raw material mixture is cured to produce polyurethane. Preferably, it is added in advance to one or both of at least two types of polyurethane forming raw materials, or it is appropriate to mix them simultaneously when the polyurethane forming raw materials are mixed. Furthermore, the siliceous filler and this additive need not be added at the same time.
For example, a method in which this additive is added to one of at least two types of polyurethane forming raw materials and a silicic acid filler is added to the other, or a method in which this additive is added to at least one of the polyurethane forming raw materials, A method of mixing a siliceous filler when mixing the forming raw materials, a method of impregnating or mixing a polyurethane-forming raw material mixture containing this additive into the siliceous filler, and other methods can be used. Of course, there is a method of adding both at the same time, for example, a method of adding this additive and a siliceous filler in advance to one of the raw materials for forming polyurethane, or a method of adding the mixture of this additive and a siliceous filler to one of the raw materials for forming polyurethane. A method of adding at least one or a mixture thereof, and other methods can be used. In the method for producing polyurethane of the present invention,
The term "presence" of the compound in the present invention "along with the siliceous filler" does not indicate the timing of addition of treated or untreated siliceous filler or additives, but rather This indicates that both are present in the polyurethane-forming raw material mixture before the reaction of the mixture is completed. Of course, if a treated siliceous filler is used, it is also present at the same time. On the other hand, when used as an additive, it may be added separately from the siliceous filler. As the silicic acid filler in the present invention, various silicic acid fillers such as those described above can be used, but
Glass fillers such as glass fibers, glass flakes, glass beads, glass microballoons, and glass powder are preferred, with glass fibers having a particularly high reinforcing effect being particularly suitable. Further, fibrous silicic acid fillers other than glass, such as asbestos, calcium silicate fibers (wollastonite), and tabular fillers such as natural mica and synthetic mica are also preferred because they have a high reinforcing effect. Taking glass fiber as an example, there are various forms, but when used in the RIM method, it needs to flow easily with the polyurethane forming raw material, so milled fibers and chopped strands of glass fiber are used. is appropriate. Similarly, when impregnating a polyurethane-forming raw material or a mixture thereof, or when introducing a polyurethane-forming raw material mixture by the RIM method or other methods after filling a mold with glass fibers in advance, the form is not particularly limited, and for example, Roving, chopped strand mats, contained strand mats, roving cloth, cloth, etc. can also be used. In addition, in the present invention, it is possible to use not only one type or one form of the silicic acid filler, but also two types of silicic acid fillers.
More than one type or form of siliceous filler can be used. The siliceous filler is present in the polyurethane-forming raw material prior to the point at which the reaction of the polyurethane-forming raw material mixture is completed. For example, a method in which it is mixed in at least one of the polyurethane forming raw materials in advance, a method in which it is mixed in at the same time when the polyurethane forming raw materials are mixed, a method in which it is mixed or immersed in the polyurethane forming raw material mixture, a method in which the polyurethane forming raw material mixture is impregnated or sprayed, etc. It is. especially
In the case of the RIM method, at least two types of liquid polyurethane forming raw materials are mixed in advance with one or more of them and RIM molding is carried out, or at least two types of liquid polyurethane forming raw materials are mixed in advance, or a fluidizable component containing a siliceous filler is used as a third component. It is preferable to use a method in which RIM molding is performed by simultaneously mixing the seed polyurethane forming raw materials during mixing and injection, or by mixing with the polyurethane forming raw material mixture immediately after mixing and injection. The amount of siliceous filler to be filled in polyurethane is not particularly limited. For methods other than RIM,
For example, in the case of methods using impregnation or mixing, extremely high loadings are possible. However, R.I.M.
In the case of molding, a certain level of fluidity is required for the silicic acid filler and components containing it to be injected into the mold, so the filling amount is often limited. It is usually filled in a molded product in an amount of 50% by weight or less, usually about 5 to 30% by weight. Of course,
More may be filled if possible. The production of the polyurethane of the invention is particularly preferably carried out by the RIM method described above. Although various RIM methods are conceivable for producing filler-containing polyurethane by the RIM method, the following two methods are preferably used. One method is to previously disperse a filler in at least one of at least two types of polyurethane-forming raw materials, and mold the polyurethane-forming raw material containing this filler by the RIM method. For example, a filler is dispersed in a component containing an active hydrogen compound such as a polyether polyol, and this component and a component containing an isocyanate compound are used for RIM.
This is a method that performs molding using a method. Of course, the component to which the filler is added in advance may be a component containing an isocyanate compound, or it may be added to both components together. Another method is to perform the RIM method using a filler-containing component as the third component. In the RIM method, two components, a component containing an isocyanate compound and a component containing an active hydrogen compound, are mixed and injected in many cases, but three or more components can also be mixed and injected. Therefore, using this method, a filler-containing and fluidizable component can be mixed and sprayed as a third component with two or more components. There are two possible methods for this method; one method is to mix the third component at the same time as the other components, and the other method is to add the third component to the mixture immediately after mixing the other components. This is a method of mixing. This third component is suitably a mixture of a filler and a liquid component or a fluidizable solid component, and it is preferable to use a part of the polyurethane forming raw material, such as an active hydrogen compound, as the liquid component. The polyurethane of the present invention is preferably produced using the RIM method, but is not limited thereto. The RIM method can mainly mold elastomers, foamed elastomers, rigid foams, semi-rigid foams, thermoplastic resins, thermosetting resins, etc., but these can also be manufactured by other methods. In particular, it is thought that hard, semi-hard, and soft foams will continue to be manufactured mainly by conventional methods. The present invention can be applied when producing polyurethane containing a silicic acid filler by a method other than RIM. Foams can be manufactured in conventional manner from polyurethane-forming raw materials containing, for example, pre-treated siliceous fillers or combinations of additives and fillers, and the foams can also be made from polyurethane-forming raw material mixtures such as treated glass fiber rovings. It can be impregnated with filler and molded. The polyurethane in the present invention is a polymer having urethane bonds, and often contains urea bonds, biuret bonds, allophanate bonds, etc. in addition to urethane bonds. Furthermore, polymers containing many bonds other than urethane bonds, such as polyisocyanurate, are also included. This urethane bond is formed by a reaction between an isocyanate group and an active hydrogen group. A blocked or masked isocyanate group does not directly react with an active hydrogen group, but once an isocyanate group is generated and reacts, it is considered as one type of isocyanate group in the present invention. Polyurethane is formed from at least two polyurethane-forming raw materials. One of them is an isocyanate compound having at least two isocyanate groups, and the other one is an active hydrogen compound having at least two active hydrogens. Each of the isocyanate compound and the active hydrogen compound may be a mixture of two or more kinds of compounds. The reaction between an isocyanate compound and an active hydrogen compound usually requires a catalyst, and basic catalysts such as amines and organometallic compounds such as organotin compounds are often used. As the isocyanate compound, at least 2
aromatic, aliphatic, with isocyanate groups,
These include hydrocarbons such as alicyclic and heterocyclic hydrocarbons, isocyanate-terminated prepolymers, modified isocyanate compounds modified with various compounds, and compounds masked or blocked with these. In particular, aromatic polyisocyanates such as TDI, MDI, PAPI, and modified polyisocyanates are often used. Although there are many types of active hydrogen compounds, compounds having a hydroxyl group, that is, polyols, are most often used. For example, polyether polyols and polyester polyols. There are also block polymers such as polymer polyols, polymer-containing polyols, hydroxyl group-containing polybutadiene, acrylic polyols, and other polymers. In addition, active hydrogen groups other than hydroxyl groups include amines and others, such as polyols treated with amines and ammonia. In addition, relatively low-molecular polyols and amine compounds are called crosslinking agents or chain extenders, and are one of the raw materials for elastomers and foams.
Often used as a seed. Many more additives are used as raw materials other than the isocyanate compound, active hydrogen compound, and catalyst. For example, in the case of foam, blowing agents and foam stabilizers are required. Other additives include, for example, colorants, mold release agents, stabilizers, flame retardants, softeners, and fillers other than siliceous fillers. Fillers other than siliceous fillers include fibrous fillers such as carbon fibers and synthetic fibers, and powder fillers such as calcium carbonate, barium sulfate, and aluminum hydroxide, which are used in combination with siliceous fillers. be able to. EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. Example The treatment agent described below is dissolved in water or an organic solvent, and a milled glass fiber (average length) is added to the solution.
140μ, fiber diameter 14μ, E glass (manufactured by Asahi Fiberglass Co., Ltd., trade name "MF-B") and stirred, then the contents were sucked out and dried to give a treatment agent adhesion of 0.1% by weight. A treated glass fiber was produced. The glass fibers to be treated were mixed with polyether polyol (molecular weight approximately 6000, number of functional groups 3, Asahi Olin Co., Ltd.) in an amount such that the glass fiber content of the final molded product was 20% by weight.
A polyol slurry was prepared by mixing 70% by weight of 1,4-butanediol, and 30 parts by weight of 1,4-butanediol, and a predetermined amount of catalyst (triethylenediamine and dibutyltin dilaurate). This polyol slurry and modified MDI (manufactured by Kasei Upjiyon Co., Ltd., product name "Isonate-")
1430L”) and the isocyanate index is 106
Molding was performed using a RIM molding machine using the following amounts. The density, bending elasticity, tensile strength, and elongation at break of this molded article were measured. Measurements were performed using the following method. Flexural modulus: ASTM D-790 Tensile strength: JIS K-6301 Elongation at break: JIS K-6301 The results are shown in the table below. Note that number 1 is an example using untreated glass fiber.

【table】

Claims (1)

[Claims] 1. A siliceous filler-containing product obtained by reacting an isocyanate compound having at least two isocyanate groups with an active hydrogen compound having at least two active hydrogens in the presence of a siliceous filler. A method for producing a polyurethane containing a silicic acid filler, characterized in that a fluorine-based surfactant or an acrylic ester or methacrylic ester of a long-chain alkyl alcohol is present together with the silicic filler. . 2. The method according to claim 1, characterized in that a siliceous filler treated with a fluorine-based surfactant or a treatment agent containing an acrylic ester or a methacrylic ester of a long-chain alkyl alcohol is used. Method. 3. The method according to claim 1 or 2, wherein the fluorine-based surfactant is an amphoteric surfactant or a cationic surfactant containing a polyfluoroalkyl group. 4. The method according to claim 1, wherein the siliceous filler is a vitreous filler. 5. The method according to claim 4, wherein the vitreous filler is glass fiber. 6. Claim 1, characterized in that the method for producing polyurethane is a reaction injection molding method.
Section method.