JPS58213034A - Siliceous filler for use in polyurethane - Google Patents

Abstract

PURPOSE:The titled filler for improving the flexural modulus and tensile strength of a molding, prepared by treating a siliceous filler with a specified treating agent. CONSTITUTION:A siliceous filler for use in polyurethane is prepared by attaching 0.001-5wt% organosilicon compound containing both a mercapto group and a hydrolyzable silane group, such as a compound of formula I or II, to a siliceous filler (e.g., glass fiber). Then, below 70wt% above filler is added to a polyurethane-forming material, and the mixture is reaction-injection-molded. EFFECT:This filler does not cause a marked increase in the viscosity of a polyurethane-forming material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention 8A relates to siliceous filling for polyurethane filling.

Polyurethane is a polymer having urethane bonds, and is mainly obtained by condensing isocyanate groups and active hydrogen groups. In the following, the polyurethane-forming raw material mainly refers to a compound having at least two isocyanate groups and a 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, especially as foams and elastomers. It is also used in paints, adhesives, fibers, artificial leather, caulking materials, thermoplastic resins, thermosetting resins, etc. Among these, silicic acid fillers are often used in polyurethane used in molded products such as foams, elastomers, and thermoplastic resins, and this is also used in polyurethane for other uses. Addition of fillers may cause nausea.

Examples of siliceous fillers include fibrous fillers such as glass fiber asbestos and calcium silicate fibers (wollastonite), glass flakes, flat fillers such as mica, glass powder, silica, talc, clay, and glass. There are powder to granular fillers such as peas and shirasu balloons.

Among these, fibrous fillers and flat fillers are particularly effective in improving the physical properties of synthetic resins, particularly in improving their strength, and are used as reinforcing fillers for synthetic resins. Powder to granular fillers are mainly used as fillers, but they also have the same effect as reinforcing fillers for synthetic resins. Among these fillers,
In particular, in order for reinforcing fillers to exhibit their reinforcing effects,
It is necessary to adhere closely to the synthetic resin. However, the filler alone does not adhere firmly to the synthetic resin, and it is usually necessary to treat its surface to improve adhesion. However, there is no universal treatment agent, and it is necessary to use an optimal treatment agent depending on the type of synthetic resin.

Not much is known about treatment agents for siliceous fillers for polyurethane. However, examples of using glass fibers for polyurethane reinforcement are known. For example, there are methods to obtain glass fiber-reinforced polyurethane foam by mixing a foamable stock solution containing polyurethane-forming raw materials and glass fibers, and methods to obtain synthetic wood by impregnating glass fiber roving with a foamable stock solution and performing pultrusion molding. be. Only 1
7. In these glass fiber reinforced polyurethane foams,
Since the strength of the polyurethane foam itself is not as high as seamers, it is thought that the effect of improving the strength by using a treatment agent for glass fibers is relatively low, and no study was conducted on the treatment agent. Another known method is to mix polyurethane elastomer and glass fiber and obtain glass fiber-reinforced polyurethane by injection molding, etc., but this method is not commonly used, and the glass fiber treatment agent for this method is not widely used. It was not considered.

In recent years, reaction injection molding has become a popular method for producing and molding polyurethane.
ng) is attracting attention. This process involves mixing at least two components, a liquid component whose main component is an isocyanate compound and a liquid component whose main component is an active hydrogen compound, immediately before the mold, injecting the mixture into the mold, and reacting and curing it in the mold to produce polyurethane. This is a molding method for obtaining molded products. 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 method, and it is expected that this molding method will become widely used in the future.

By this reaction injection molding (hereinafter referred to as R-M) method,
Molding of filler-containing polyurethanes has been considered. In particular, the biggest challenge is to use glass fiber milled fibers or chopped strands as fillers to obtain glass fiber-reinforced polyurethane V-tanned molded products.

Regarding the R/M method for glass fiber reinforced polyurethane, some proposals have already been made regarding the equipment and methods. However, regarding glass fiber for this,
At present, nothing other than its shape such as length and diameter and the amount of polyurethane to be filled have been investigated. Therefore, the present inventors specifically investigated the treatment agent for glass fibers in the molding of glass fiber reinforced polyurethane using R-M.

As a result, it was found that the reinforcing effect and other properties of polyurethane by glass fibers treated with a treatment agent vary widely depending on the treatment agent used.

A large number of compounds and combinations thereof are known as processing agents for siliceous fillers for filling synthetic resins. Therefore, the present inventor investigated the treatment effects of many organosilicon compounds that are expected to have a high affinity with silicic acid fillers.

As a result, it was found that among many organosilicon compounds, organosilicon compounds having a mercapto group and a hydrolyzable silane group are particularly effective. The present invention is a silicic acid filler that is added to a polyurethane forming raw material in polyurethane molding by reaction injection molding, which is a silicic acid filler treated with a processing agent containing this organosilicon compound.

The organosilicon compound of the present invention improves the adhesion of siliceous fillers to polyurethane. Not all conventional hydrolyzable silane group-containing compounds improve this adhesion, and on the contrary, they may sometimes reduce the adhesion. It is thought that the cause of the decrease in adhesion is that active sites such as hydroxyl groups that the silicic acid filler originally has on its surface disappear. The degree of improvement in adhesion can be measured, for example, by modulus (modulus of elasticity), tensile strength, etc. That is, the adhesion is measured by measuring the modulus tensile strength, etc. of polyurethane filled with fillers treated with various treatment agents, and comparing the values. Using glass fiber as a filler, the present inventor molded a polyurethane elastomer filled with glass fiber by the R/M method or an equivalent method, and measured its bending modulus and tensile strength.

The flexural modulus of polyurethane elastomers containing untreated glass fibers increases as the glass fiber loading increases. In the case of glass fibers treated with a treatment agent, the bending modulus also improves depending on the amount of filling, but when compared with the same amount of filling, the bending modulus changes depending on the type of treatment agent. Depending on the treatment agent, the bending modulus may be lower than that using untreated glass fiber, and such treatment agents are ineffective. However, if the purpose of the treatment agent is other than modulus improvement, such a treatment agent is not necessarily ineffective. The purpose of the present invention is to improve this modulus, and as a result of researching and examining processing agents that have a high modulus, we have discovered the above-mentioned specific organosilicon compound. However, it was also found that the modulus improvement effect was not necessarily in a parallel relationship with the amount of treated filler. For example, fillers treated with the same treatment agent’! f - Comparing the flexural modulus of a polyurethane elastomer filled with a certain amount and the flexural modulus of a polyurethane elastomer filled with an even larger amount with that of a polyurethane elastomer filled with the same amount of untreated filler. Even if the flexural modulus improvement rate of potatoes is low, there are cases where the flexural modulus improvement rate of potatoes with a large amount of filling is remarkable. Although the reason for this is not clear, in the present invention, if the modulus improvement effect at a certain filling amount is high, the effect of the processing agent is considered to be low. This is because treated fillers can be used at effective loadings, as long as this loading does not deviate significantly from the loadings normally used.

Hydrolyzable silane groups are converted into silanol groups (
>5iOH) is a functional group that can generate a group. This silanol group is said to have a high affinity with the surface of the siliceous filler, and therefore, the organosilicon compound of the present invention requires a functional group that can form a silanol group by hydrolysis. Examples of the hydrolyzable silane group include a silane group having a [->5l-o-c<] bond such as an alkoxysilane group, and a silane group having a [')sl-o-a-] bond such as a 1-acyloxysilane group. , chlorosilane group, etc. (->5i
-z ] (z: halogen) There is a silane group having a bond1, these hydrolyzable functional groups bonded to a silicon atom have 1 to 3, especially 3 bonded to a silicon atom, and these 2 or # The functional groups bonded to the three silicon atoms 'i may be different. The silicon atom 1ic-bonded brukoxy group or acyloxyl group may also be various derivatives. For example, tris(methoxyethoxy)silane group [-5t(oaln, oon, )3] hikodo. As the hydrolyzable silane group, alkoxysilane groups and derivatives thereof are most preferred. Although the number of carbon atoms in the hydrolyzable organic group in these hydrolyzable silane groups is not particularly limited, it is usually 6 or less, particularly preferably 4 or less. For example, in the case of an alkoxysilane group, methoxy, ethoxy, propoxy, and butoxy groups are preferred.

The organosilicon compound in the present invention has a mercapto group (-OH) in addition to the hydrolyzable silane group. The mercapto group is not directly bonded to the silicon atom of the hydrolyzable silane group, but is bonded to the carbon atom following the silicon atom. The carbon atom following this silicon atom is a hydrocarbon such as aliphatic, alicyclic, aromatic, or heterocyclic, or a derivative thereof. Examples of derivatives include hydrocarbons containing functional groups other than those mentioned above, such as ester groups, ether groups, ketone groups, and amino groups. Furthermore, the functional groups in the present invention may be a combination of two or more of the same or different functional groups.

The most preferred hydrolyzable silane group, the alkoxysilane group, is -at(on)m(y)3-m (m''~3
R is an alkyl group and Y is an organic group bonded to a silicon atom other than an alkoxy group. However, m is an integer within one molecule, and in a mixture of molecules with different m, the average m may not be an integer. Furthermore, in the case of a mixture with a compound without an alkoxy group, m may be 1 or less.

Various organic groups can be used as Y, and the type thereof is not limited, but preferably an organic group in which a silicon atom and a carbon atom are directly bonded, such as an alkyl group, or an organic group in which a silicon atom and a carbon atom are bonded through an oxygen atom. It is an organic group, especially an alkyl group.

Specific examples of organosilicon compounds of the present invention are shown below, but the present invention is not limited only to these compounds.

(a): Ha-(OH2)1-81(00■s)
m.

(b): He-(OHz)*-81(
00mHi)sThe symbols in (a) and (b) are the compounds used in the examples.

The siliceous filler treated with the treatment agent containing the organosilicon compound of the present invention does not significantly increase the viscosity of the siliceous filler-containing polyurethane-forming raw material after being mixed with the polyurethane-forming raw material. This is a particularly necessary property when this filled polyurethane-forming feedstock is used in the RIM process. In the R/M method, the polyurethane forming raw material is pressurized by a pump and injected, so it is circulated between the injection machine and the raw material tank even when it is not normally being injected, so if the viscosity is high, the circulation may be interrupted. This is because the injection pressure has decreased. The treated fillers of the present invention do not significantly increase the viscosity compared to their untreated counterparts; some even decrease the viscosity.

As the silicic acid filler for polyurethane in the present invention, various silicic acid fillers as described above can be used, but
Glass fillers such as glass fibers, glass flakes, glass beads, glass microballoons, and glass powder are preferred, and glass fibers with a high reinforcing effect are particularly suitable. Further, fibrous fillers other than glass, such as flat fillers such as asbestos, calcium silicate fibers (wollastonite), and mica, are also preferred since they have a reinforcing effect. Glass fibers come in various forms, but for use in the RIM method, it is preferable that they flow easily with the liquid component, so milled fibers and chopped strands of glass fibers are suitable. Similarly, milled fibers and chopped strands are suitable when used by pre-mixing with the polyurethane forming raw material or when mixed at the same time as the hardening of the polyurethane forming raw material3.In addition, glass fibers are pre-filled into the mold. In the case where the polyurethane forming raw material is introduced after the polyurethane forming material is added, its form is not particularly limited, and various forms such as roving, chopped strand mat, continuous strand mat, roving cloth, and cloth can be used. can. In addition, the filler of the present invention has 2
It is also possible to use more than one species in combination.

The processing agent containing the organosilicon compound is usually used in the form of a solution or dispersion. The type of solvent or dispersion medium is not particularly limited, and suitably used are, for example, water, lower alcohols, lower halogenated hydrocarbons, ethers, ketones, and other liquids that can dissolve or disperse organosilicon compounds.

The solvent or dispersion medium may be one type or a mixture of two or more types. Further, in the case of a compound containing an isocyanate, a solvent containing active hydrogen such as water or alcohol is unsuitable because it causes a reaction. Moreover, the treatment agent containing at least one type of organosilicon compound according to the present invention may further contain other additives. Examples include pH adjusters, viscosity adjusters, surfactants, dispersion stabilizers, lubricants, antistatic agents, antifoaming agents, fine particle powders, and the like. Furthermore, organic silicon compounds other than the aforementioned organic silicon compounds, synthetic resins such as epoxy resins, etc. may be added. The concentration of the organosilicon 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 be improved commensurately, so there will be limitations. Usually, the concentration of organosilicon compound in the treatment agent is approximately α001 to 10% by weight,
Particularly preferred is α1 to 50 weight ratio.

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 treated milled fibers or chopped strands.

The amount of the hydrolyzable silane group-containing compound 1 attached to the treated filler is not particularly limited as long as it is attached to the extent that the effect of the treatment is exhibited. However, when the filler is glass fiber, for example, it is appropriate to have a weight of r101 to [L5], so it is generally considered that the effect will be exhibited at about α001 to 50% by weight.

The treated siliceous filler of the present invention integrates the polyurethane forming raw material and filler prior to polyurethane formation.

That is, it is used by mixing a pre-treated silicic acid filler into the polyurethane forming raw material, or by mixing a treated silicic acid filler at the same time as the polyurethane forming raw material is mixed. The reason why it is preferable to use the silicic acid filler of the present invention in these methods is that the object to which the silicic acid filler is contained is a liquid substance with relatively low viscosity, so it is easy to mix it in), and the energy required for mixing is low. In addition, there is a high possibility that the treatment agent on the surface of the filler reacts with the polyurethane-forming raw materials at the same time, resulting in strong adhesion between the polyurethane and the treatment agent. This is because it is thought to improve strength.

The method of incorporating the treated siliceous filler into the polyurethane-forming raw material or mixture thereof is not particularly limited. For example, in order to pre-contain a filler in at least one of the raw materials for forming polyurethane, it is common to mix the two together. . Various methods can be used to incorporate the filler into or simultaneously with the mixing of the polyurethane-forming raw materials.

Usually, a method is used in which the raw materials for forming polyurethane are mixed simultaneously by stirring or the like. When the polyurethane is a non-foam product, such as a thermoplastic in an elastomer, it is preferable to avoid introducing foam when using these methods. For example, it is preferable to use a method such as mixing the polyurethane forming raw material and the filler under reduced pressure, or defoaming the mixture under reduced pressure.

The treated siliceous fillers of the present invention are used as fillers for polyurethanes molded by the R-M process. In this case, as a method for incorporating the treated siliceous filler of the present invention into the polyurethane-forming raw material or the mixture thereof in advance or simultaneously, any of the methods described herein can be used. Usually, a filler is used by pre-mixing one or both of at least two polyurethane-forming raw materials. That is, a filler is mixed in advance into a liquid component whose main component is an active hydrogen compound and/or a liquid component whose main component is an incyanate compound. Depending on the treatment agent, there are treatment agents that react with isocyanate compounds or react with active hydrogen compounds (isocyanate groups, etc.), giving or receiving adverse effects, so it is preferable to use siliceous fillers treated with compounds containing isocyanate groups. Other than these, they are used by being mixed in advance into a liquid component containing an active hydrogen compound as a main component.

When there is little risk of adverse effects or when the amount of filling is to be increased, the isocyanate compound can be mixed into the liquid component whose main component is an isocyanate compound, or mixed into both liquid components. It is also possible to prepare a masterbatch by pre-mixing a comparatively large amount of filler and a comparatively small amount of polyurethane forming raw materials and apply this to the R/M method.

That is, at least two polyurethane-forming raw materials are
This masterbatch can be mixed in when the liquid components of the seeds are mixed or after mixing and before being injected into a mold.

The amount of the filler of the present invention filled into the polyurethane is not particularly limited; however, in the RIM method, if the amount filled is extremely large, the viscosity of the raw material for forming the polyurethane increases, making mixing and injection difficult.

Therefore, in this case, the III'&:t of the filler of the present invention in the MP polyurethane molded article is preferably 70% by weight or less, and 1r-5 to 50% by weight is appropriate.

The polyurethane/tan in the present invention is a polymer having a urethane bond, and often contains a urea bond, a billet bond, an allophanate bond, etc. in addition to the urethane bond.

The formulas also include polymers containing many bonds other than urethane bonds, such as polyisocyanurate. This polyurethane bond is formed by a reaction between an isocyanate group and an active hydrogen group. Polyurethane t is formed from at least two types of 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. The isocyanate compound and the active hydrogen compound may each be a mixture of two or more kinds of compounds. The reaction between isocyanate compounds and active hydrogen compounds usually requires a catalyst, and basic catalysts such as amines and organometallic compounds such as organotin compounds are often used.

Examples of isocyanate compounds include aromatic, aliphatic, alicyclic, and heterocyclic hydrocarbons having at least two isocyanate groups, as well as modified isocyanate compounds modified with incyanate-terminated prepolymers and various compounds. and so on. In particular, TD, MDI, PAP, and other aromatic 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. In addition, there are also polymers such as block polymers such as polymer polyols, polymer-containing polyols, hydroxyl group-containing polybutadiene, and acrylic polyols.

Active hydrogen groups other than hydroxyl groups include amines and others such as sb, such as polyols treated with amines and ammonia. In addition, relatively low molecular weight polyols and amine compounds are also called crosslinking agents or chain extenders, and are often used as raw materials for elastomers and foams. Many more additives are used as raw materials other than the isocyanate compound, active hydrogen compound, and catalyst. For example, foams require blowing agents or blowing agents. Other additives include, for example, colorants, mold release agents, stabilizers, flame retardants, softeners, and fillers other than siliceous fillers. Examples of fillers other than siliceous fillers include fibrous fillers such as carbon fibers and synthetic fibers, powder fillers such as calcium carbonate, barium sulfate, and aluminum hydroxide, and siliceous fillers. Can be used together.

The present invention will be specifically explained below using examples, reference examples, and examples, but the present invention is not limited only to these examples. In addition, although examples and reference examples are written together,
The production of treated glass fibers is an example, and the molding and evaluation of molded products using the R/M method or an equivalent method are reference examples.

Examples 1 to 2 Glass fiber treatment method The organosilicon compound described later is dissolved in a solvent at a predetermined concentration to prepare a treatment agent liquid 1200- (the type of f1 medium and the concentration of the organosilicon compound are described later).

While stirring this solution with a homomixer, a 20-neck milled fiber (MF-B manufactured by Asahi Fiberglass ■: average length 140 μm, fiber diameter 10 μm, E glass) was gradually added. When the glass fibers are sufficiently dispersed, stop stirring, filter the contents with suction, take out the filter cake, and calculate its weight [W
g]. Next, loosen the filter cake and add 80
Dry in oven at °C.

The amount of treatment agent attached is calculated as follows.

The type of treatment agent, treatment conditions, and amount of treatment agent deposited are listed in Table 1 below, along with reference examples.

Reference Examples 1-2 Manufacturing method and evaluation method of glass fiber reinforced polyurethane elastomer.

The above-treated milled glass fibers (35.4 or 50.29) were degassed in a pressure vessel under a reduced pressure of 10 wHg, and then under the same pressure a polyether polyol (trivalent with a molecular weight of about 5000) was degassed. Polyether polyol (manufactured by Asahi Olin ■) 71f was added dropwise and mixed and stirred. The following liquid mixture was further added to the resulting polyether polyol/milled fiber mixture and stirred under reduced pressure in the same manner.

Ethylene glycol 19 9 molecular sounds approx. 1
500 trivalent polyether polyol (Asahi Olin■
(manufactured by) y, s with a molecular weight of approximately 700
Modified MDI (manufactured by Kasei Upjohn ■, product name 1 isonate-145L') 10α7f (isocyanate index After adding 102) and stirring under reduced pressure in the same manner, triethylenediamine α3f and dibutyltin dilaurate 006f were added as catalysts and stirred for several seconds,
Shot into the mold.

Additionally, glass fiber milled fibers treated with an organosilicon compound having an incyanate group and a hydrolyzable silane group are used in addition to the modified MD, and this glass fiber-containing modified MDI and the polyol system liquid having the above composition are mixed together. Mixed in the same manner as above, added catalyst and shot into mold.

The obtained molded product contains 15% by weight of milled fiber in the molded product when the milled fiber is 354f.
When t, 20 weight factor milled fibers are included.

This method is known to be equivalent to the molding of polyurethane elastomers by the RIM method, and by evaluating the molded products obtained by this method, the physical properties of the elastomer manufactured by the R/M method can be evaluated. sell. The density bending modulus, tensile strength, and elongation of the glass fiber-reinforced polyurethane elastomer obtained by this method were measured by the following methods.

Bending modulus °mu8TM D-790 tensile strength 1
&': JT Japan K-4301 Results The results of Examples 1 and 2 and Reference Examples 1 and 2 above were
Shown in the table. In addition, the types of processing agents (,) to 弽) correspond to the symbols added in front of the chemical formulas shown as specific heavy compounds in the above specification, and indicate the compounds.

Comparative Examples 1 to 5 Using untreated glass fibers and glass fibers treated in the same manner as in Examples using the following hydrolyzable silane group-containing compound, polyurethane molded products containing the glass fibers were prepared by the method in Reference Examples. The results of molding and measuring its physical properties are shown in Table 1 below.

Reference Example 6 R-M molding was performed using the following polyol system liquid and incyanate liquid in a test RIM molding machine.

Polyol system liquid: Ethylene glycol 19N triethylenediamine [14# dibutyltin dilauv-)
aoay Freon-113l Isocyanate liquid The above polyol system liquid and isocyanate liquid were each placed in the tank of the R/M molding machine, and the flow rates were adjusted so that the isocyanate index was 102.
It was injected into the mold under the following conditions. .

Molding conditions: Liquid temperature: 40° C. Mold temperature: 60° C. Demolding time: 5 minutes The obtained molded product was post-cured at 120° C. for 1 hour, and the physical properties of the molded product were evaluated. The results are shown in Table 2 below.

For comparison, the test results of an example in which no glass fiber milled fiber was used and an example in which an untreated glass fiber milled fiber was used are also shown in Table 2.

Table 2

Claims (1)

[Claims] 1. Molding of polyurethane by reaction injection molding, characterized in that the filler is a siliceous filler treated with a treatment agent containing an organosilicon compound having a mercapto group and a hydrolyzable silane group. A siliceous filler added to polyurethane forming raw materials. z The filler according to claim 1, wherein the hydrolyzable silane group is an alkoxysilane group. (5) The filler according to claim 1, wherein the siliceous filler is a vitreous filler. 4. The filler according to claim 3, wherein the vitreous filler is glass fiber.