JPH1177732A - Manufacture of polyurethane resin molding containing inorganic reinforcing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the sedimentation rate of glass fiber to such an extent that any inconvenience does not occur when the glass fiber is actually used and also prevent the glass fiber from imparting an unfavorable effect to the moldability and the physical property of a final finished product, when a polyurethane resin molding is to be manufactured by a reactive injection molding process using an active hydrogen compound component to which an inorganic reinforcing material is added and an isocyanate compound component. SOLUTION: In the method for manufacturing a polyurethane resin molding containing an inorganic reinforcing material by which it is possible to manufacture a polyurethane resin using a reactive injection molding process with an active hydrogen compound component to which the inorganic reinforcing material is added and an isocyanate compound component, the active hydrogen compound component comprises a mixture of an active hydrogen compound having the average number of functional groups of 2-5 in a molecule and the average hydroxy group value of 300-700 mgKOH/g in the part excepting the inorganic reinforcing material, a first needle-like inorganic reinforcing material with an average diameter of 5-15 μm and an average length of 50-200 μm, a second needle-like inorganic reinforcing material with an average diameter of 0.1-0.5 μm and an average length of 10-20 μm and a catalyst. The active hydrogen compound, the first and the second needle-like inorganic reinforcing material are in the mixing ratio of 60-80%, 15-39% and 1-5% respectively to the total weight of the mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a molded article of a polyurethane resin or a polyurethane polyurea resin containing an inorganic reinforcing material.

[0002]

2. Description of the Related Art Various reinforcing materials are used in polyurethane and polyurethane polyurea resins used as automobile bumper covers and door trim base materials to secure rigidity. One of them, glass fibers having an average length of 50 to 150 μm, is used in particular because of its high rigidity, good dimensional stability and low-temperature impact resistance.

As a method for producing such a polyurethane or polyurethane polyurea resin, a high molecular weight active hydrogen component such as a polyether polyol is mixed with a chain extender, a crosslinking agent, a catalyst, a foaming agent and other additives together with the glass fiber. Then, it is common practice to obtain the obtained slurry-like mixture by so-called Reaction Injection Molding (RIM) in which an isocyanate component such as diphenylmethane diisocyanate is subjected to collision stirring under high pressure and then injected into a mold. Have been done.

[0004] At this time, a problem is that the glass fibers mixed into the polyol side have a remarkably different specific gravity from the polyol and other additives, so that the glass fibers settle and separate over time. In order to prevent such sedimentation and separation, at the actual molding site, stirring is performed in the raw material tank,
Low pressure circulation is performed in the piping. However,
Such measures may not be feasible due to some human or mechanical problems, in which case the settled glass fibers will clog the piping and the like. It is not easy to remove the glass fiber from the clogged pipe, and it requires a great deal of labor and cost such as disassembly of the molding machine and replacement of the pipe. In addition, in order to facilitate these operations, a pump is added to the molding machine in advance, and a drain is installed when the clogging is temporarily stopped.
Huge equipment costs must be spent. In addition, in molding factories, work has often been suspended for one week or more due to the increase in long-term leave. However, as a countermeasure, continuous circulation or removal of raw materials and removal of raw materials that do not contain glass fiber have been conducted. Inefficient work such as filling the equipment and filling the glass fiber-containing material again on the day after the holidays.

[0005]

Therefore, if the sedimentation of the glass fiber can be prevented or delayed, such labor and cost can be greatly reduced. By the way, the sedimentation speed of the particles in the liquid can be obtained from the following Storkes equation.

[0006]

[Formula 1] V = g (ρs−ρl) D / 18μ

Here, V is the sedimentation velocity, D is the equivalent sphere diameter, g
Is the gravitational acceleration, μ is the liquid viscosity, ρs is the particle density, and ρ1 is the liquid density.

That is, by increasing the liquid viscosity and the liquid density, the sedimentation of particles can be prevented or delayed. However, the increase in the viscosity of the liquid, that is, the active hydrogen component mixture, results in poor stirring during molding and a decrease in moldability. In addition, there is no liquid raw material such as a polyol having a density close to that of glass fiber, and even if it is present, it eventually increases the weight of the product, so that its use is not economically meaningful. In addition, regarding the size of the glass fiber corresponding to D in the above formula, a certain amount (50 μm
Above), which is also limited in terms of settling velocity.

In view of the foregoing, the present invention provides a low sedimentation rate that reduces the sedimentation speed of glass fibers to such an extent that no inconvenience occurs in practical use and does not impair the moldability and physical properties of the final product. An object of the present invention is to provide a method for producing a polyurethane resin molded article containing a conductive inorganic reinforcing material.

[0010]

Means for Solving the Problems As a result of earnest studies, the present inventors have found that by adding a small amount of another fine reinforcing material, for example, potassium titanate whisker, to a conventional mixed raw material, low sedimentation and originality can be achieved. It has been found that a polyurethane or polyurethane polyurea resin raw material which maintains performance can be obtained. That is, the present invention provides a method for producing a molded article of a polyurethane resin or a polyurethane polyurea resin by a reaction injection molding method from an active hydrogen compound component to which an inorganic reinforcing material is added and an isocyanate compound component, wherein the active hydrogen compound component is An active hydrogen compound having an average number of functional groups of 2 to 5 in the molecule and an average hydroxyl value of 300 to 700 mgKOH / g in a portion excluding the inorganic reinforcing material, a first compound having an average diameter of 5 to 15 μm and an average length of 50 to 200 μm;
A mixture containing a second needle-shaped inorganic reinforcing material having an average diameter of 0.1 to 0.5 μm and an average length of 10 to 20 μm and a catalyst, and an active hydrogen compound, a first and a second. The mixing ratio of the acicular inorganic reinforcement is 60 to 80%, 15 to 39% and 1%, respectively, based on the weight of the total mixture.
-5%.

The part of the active hydrogen compound component mixture excluding the inorganic reinforcing material contains the active hydrogen compound (for example, polyalkylene oxide polymer = polyether polyol) and a reaction catalyst, and further has a chain extension depending on the resin molded article to be treated. Agents, crosslinking agents, foaming agents, etc., and the average hydroxyl value thereof is preferably 300 mgKOH / g to 700 mgKOH.
/ G, the average number of functional groups of the active hydrogen compound is 2 to 5, more preferably the average hydroxyl value is 400.
mgKOH / g to 600 mgKOH / g, and the average number of functional groups is 3 to 4. Average hydroxyl value is 300mgKOH
/ G, the obtained polyurethane polyurea polymer is too soft and does not satisfy required physical properties such as rigidity required for door trim and the like. Conversely, when the average hydroxyl value is 7
If it is greater than 00 mg KOH / g, the resulting polymer is also brittle and elastic, which is also not practical. Similarly, if the average number of functional groups (the average value of the number of active hydrogens per molecule) is 2 or less, a polyurethane polyurea polymer having the required physical strength cannot be obtained. The viscosity of the mixture becomes high, which is not only practically extremely difficult to use, but also makes the resulting polymer brittle. The above-mentioned active hydrogen component mixture generally comprises a polymer active hydrogen compound, a chain extender, a cross-linking agent, a catalyst, a foaming agent and other auxiliaries and reinforcing materials. Examples of the typical components are shown below. The description in the examples below is not intended to limit the invention claimed in this application.

The most typical active hydrogen components are polyoxyalkylene polymers, so-called polyether polyols, but also low molecular weight active hydrogen compounds such as monoethylene glycol, diethylene glycol, propylene glycol, 1,3- and 1-hydrogen. , 4-butanediol, 1,
Dihydric alcohols such as 6-hexanediol; glycerin, trimethylolpropane, triethylolethane,
Trihydric alcohols such as hexanetriol and triethanolamine; pentaerythritol, methylglycoside,
Also included are tetrahydric alcohols such as diglycerin, and sugar alcohols having higher functional groups such as pentitols such as adonitol, arabitol, xylitol; sorbitol, mannitol, iditol, talitol,
Hexitol such as dulcitol; saccharides such as monosaccharides such as glucose, mannose, fructose and sorbose; oligosaccharides such as sucrose, crehalose, lactose and raffinose; pyrogallol, hydroquinone,
Monocyclic polyphenols such as phloroglucin; bisphenols such as bisphenol A and bisphenol sulfone; and condensates of phenol and formaldehyde (novolak). Examples thereof include amines, such as ammonia; alkanolamines such as mono-, di- and tri-ethanolamine, isopropanolamine, and aminoethylethanolamine; and C1-C20.
Alkylamines, aliphatic amines such as C2-C6 alkylenediamines such as ethylenediamine, propylenediamine, and hexanemethylene; aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline, diphenyletherdiamine, and other aromatic amines Alicyclic amines such as isophoronediamine, cyclohexylenediamine, dicyclohexylmethanediamine, etc .; aminoethylpiperazine and other heterocyclic amines alone or as an arbitrary mixture thereof, and a catalyst such as potassium hydroxide. And those obtained by ring-opening polymerization of propylene oxide, ethylene oxide, butylene oxide, and mixtures thereof. If necessary, primary hydroxyl groups or secondary hydroxyl groups of polyether polyols may be used. Hydroxyl aliphatic amino group, an aliphatic imino group, an aromatic continue amino group, it may also be used those obtained by converting the aromatic imino group. Alternatively, part or all of the polyether polyol may be replaced with an aliphatic and aromatic polyester polyol.

As the chain extender, monoethylene glycol, diethylene glycol, propylene glycol,
1,4-butanediol, 1,6-hexanediol,
Glycols such as 2,2,4-trimethyl-1,3-pentanediol and chain diamines.

Examples of the crosslinking agent include low molecular weight polyhydric alcohols such as glycerin and diglycerin; amino alcohols such as diethanolamine and triethanolamine; aliphatic siamines such as ethylenediamine; 1,3,5-triethyl-2,6- Diaminobenzene, 1-methyl-3,5
-Diethyl-2,4-diaminobenzene, 1-methyl-
Examples thereof include aromatic diamines such as 5-t-butyl-2 and 4-diaminobenzene and those having three or more functional groups.

As the catalyst, tertiary amines generally used in the production of urethane resins, such as triethylenediamine, tetramethylhexamethylenediamine, N, N-dimethylethanolamine, bis (dimethylaminoethyl) ether, etc .; Catalysts such as dibutyltin dilaurate, dibutyltin dimercaptide, dimethyltin dimercaptide, dibutyltin diacetate, and other metal catalysts (lead octylate) are used.

Examples of the blowing agent include water (carbon dioxide chemically produced from water and polyisocyanate) or carbon dioxide dissolved in the mixture, air, nitrogen gas or carbon dioxide contained in the mixture. In addition to carbon dioxide generated by thermal decomposition during the production of urethane resins from salts with amines and other bases, a general physical blowing agent, ie, CFC-1
Chlorofluorocarbons (CFCs), HCFC-
Hydrochlorofluorocarbon (HCF 141b)
C) and hydrocarbons such as pentane. Various conventional additives can be added to the active hydrogen compound component mixture. For example, foam stabilizers, internal release agents, compatibilizers,
There are ultraviolet absorbers, coloring agents and the like.

Examples of the first acicular inorganic reinforcing material mixed in the active hydrogen compound component mixture include glass fiber milled fiber, cut fiber glass, wollastonite, and mineral fiber. From the viewpoint, glass fibers are more preferable, and the size thereof is suitably an average diameter of 5 to 15 μm and an average length of 50 to 200 μm, more preferably an average diameter of 7 to 12 μm and an average length of 100 to 150 μm. Average diameter of 5 μm or less,
Alternatively, when the average length is 50 μm or less, the degree of reinforcement obtained is small, and the viscosity of the mixture increases, which is not suitable for use. On the other hand, when the average diameter is 15 μm or more, or the average length is 150 μm or more, the sedimentation speed is too fast,
Or, the orifice of the reaction injection molding machine is clogged, which is also unsuitable for use.

As the fine second inorganic reinforcing material used together with the first inorganic reinforcing material, mention may be made of potassium titanate whiskers, talc, etc., but potassium titanate whiskers are more preferable in terms of preventing sedimentation. The size is 0.1 to 0.5 μm in average diameter and 5 to 1 in average length.
5 μm, more preferably an average diameter of 0.2 to 0.4 μm
m and an average length of 10 to 15 μm are suitable. When the average diameter is 0.1 μm or less and the average length is 10 μm or less, economy is lacking, and the average diameter is 0.5 μm or more and the average length is 15 μm or less.
If it is not less than μm, it is not possible to prevent sedimentation of the first inorganic reinforcing material having a large size.

The mixing ratio of the active hydrogen compound and the first and second inorganic reinforcing materials is usually 60 to 80% by weight of the total mixture weight and 15 to 39% by weight of the first inorganic reinforcing material. %, 1 to 5 of the second inorganic reinforcing material
%, More preferably 65 to 75%, 20 to 35%, and 1 to 4%, respectively.
When the amount of the active hydrogen compound is 60% by weight or less, the elasticity and impact resistance of the produced polyurethane or polyurethane polyurea polymer product are lowered, and the product cannot be put to practical use. Conversely, when the amount of the active hydrogen compound is 80% by weight or more,
Problems arise in the rigidity and dimensional stability of such polymer products. Regarding the weight ratio of the first inorganic reinforcing material and the second inorganic reinforcing material, the latter is suitably in the range of 2.5% to 25% of the former, and if it is 2.5% or less, no effect is exhibited, Conversely, if the content is 25% or more, the reinforcing function of the first inorganic reinforcing material will not be sufficiently exhibited, and the quality of the final product, polyurethane or polyurethane polyurea polymer, will be reduced.

Although any known organic di- or polyisocyanate can be used as the isocyanate component to be reacted with the above mixture to obtain the polyurethane polyurea polymer, the preferred type is an aromatic polyisocyanate. Examples, without limitation, are: m- and p-phenylenediisocyanates, 2,4
-And 2,6-toluene diisocyanate and their isomer mixtures, 4,4'-methylenebis (phenylisocyanate), 2,4-methylenebis (phenylisocyanate), and mixtures of these methylenebis (phenylisocyanate) isomers, Methylene bis (phenyl isocyanate), polyphenylene polymethylene polyisocyanate known as crude MDI, 3,
3'-dimethyl-4,4'-diisocyanatodiphenylmethane; methylene bis (phenylisocyanate) in liquefied form, especially for example 4,4'- with carbodiimide catalyst
A liquefied form such as carbodiimide-containing 4,4'-methylenebis (phenylisocyanate) having an isocyanate equivalent of 130-180, prepared by heating methylene bis (phenylisocyanate) and converting the isocyanate portion to carbodiimide (about 30% Up to 2,4
4,4′-methylenebis (phenylisocyanate); dipropylene glycol in small amounts (0.04-0.2 equivalents per isocyanate equivalent);
4,4'-methylenebis (phenylisocyanate) in liquefied form reacted with low molecular weight glycols such as tripropylene glycol and mixtures thereof;
0000, a polyalkyleneoxy polyol (polyether polyol), a polytetramethylene glycol having a molecular weight of 600 to 5,000, and a molecular weight of 500 to 800.
Isocyanate-terminated prepolymers having an isocyanate content of 9 to 20% by weight prepared from polyols having a functionality of 2-3 selected from polyester polyols of 0. Preferred isocyanate components are blends or mixtures of the above-mentioned polyisocyanates, wherein the weight ratio of such an isocyanate component to the active hydrogen compound component mixture containing inorganic reinforcing material (mixture according to claim 1) is 0.1%. 7 to 1.3,
Preferably, it is in the range of 0.8 to 1.2.

The inorganic reinforcing material-containing raw material obtained according to the present invention has a lower sedimentation speed of the inorganic reinforcing material than practically used only with a relatively large-sized inorganic reinforcing material, and has a low level of practical use. A molded article of a polyurethane or polyurethane polyurea resin obtained by reaction injection molding with an isocyanate has physical properties equivalent to those using an ordinary inorganic reinforcing material having a large size.

[0022]

【Example】

Examples 1-3 As a mixture of active hydrogen compound components, a hydroxyl value of 560 mgK
OH / g polyol having an average number of functional groups of 3 (Spectrim RL-2101 manufactured by Mitsubishi Chemical Dow), glass fiber having an average diameter of 10 μm and an average length of 100 μm as a first inorganic reinforcing material, and an average diameter as a second inorganic reinforcing material A potassium titanate whisker having a thickness of 0.3 μm and an average length of 16 μm was used. The weight ratio of this active hydrogen compound: glass fiber: potassium titanate whisker is 70: 27: 3.

The fluidity was measured by taking 250 g of each sample in a 200 ml measuring cylinder, keeping the temperature at 25 ° C., tilting the cylinder after 1 day and 5 days, measuring the amount of the flow out, and comparing the amount by weight% with respect to the total amount. The sedimentability of the inorganic reinforcement is 2
Using a sample of 250 g each collected in a 00 ml measuring cylinder and kept at 25 ° C., the volume of the solid component settled and deposited on the bottom of the cylinder after 1 day, 3 days and 5 days was measured, and expressed as a percentage of the total volume of the mixture. Compared. The result is Example 2,
The results are shown in Table 1 together with those of Example 3 and Comparative Example 1. Comparative Example 1 In Example 1, the same mixture was used except that it did not contain potassium titanate whiskers.

[0024]

[Table 1]

In Example 2, the procedure of Example 1 was repeated using talc having an average particle size of 1 μm instead of the potassium titanate whisker in Example 1. In Example 3, the procedure of Example 2 was repeated, except that the amount of talc was changed to 6% by weight.

[0026]

As described above, according to the present invention, the capital investment cost for constantly circulating the raw material in the pipe can be reduced. Since the circulation can be stopped even on holidays, dynamic fuel consumption can be reduced.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 75:00

Claims (4)

[Claims] 1. A method for producing a polyurethane resin molded article containing an inorganic reinforcing material, the method comprising producing a polyurethane resin molded article by a reaction injection molding method from an active hydrogen compound component to which an inorganic reinforcing material is added and an isocyanate compound component. The hydrogen compound component has an average number of functional groups in the molecule of 2 to 5
And the average hydroxyl value of the portion excluding the inorganic reinforcing material is 3
Active hydrogen compound having an average diameter of 5 to 15 μm and an average length of 50 to 200
μm of the first needle-shaped inorganic reinforcing material, having an average diameter of 0.1 to 0.1 μm.
5 μm, a mixture containing a second acicular inorganic reinforcing material having an average length of 10 to 20 μm and a reaction catalyst, wherein the mixing ratio of the active hydrogen compound and the first and second acicular inorganic reinforcing materials is a total mixture. A weight of 60 to 80%, 15 to 39% and 1 to 5%, respectively. 2. The method according to claim 1, wherein the first acicular inorganic reinforcing material is a glass fiber, and the second acicular inorganic reinforcing material is a potassium titanate whisker. 3. The method according to claim 1, wherein the active hydrogen compound component mixture contains an auxiliary selected from a chain extender, a crosslinking agent and a foaming agent. 4. The method according to claim 1, wherein the polyurethane resin is a polyurethane polyurea resin.