JP2008179746A - Method for producing polyol compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyol compound capable of producing a polyurethane elastomer capable of developing excellent sealing performance without causing insufficient curing even when formulating a thickener component, especially suitable for sealing materials, in a polyol compound comprising a reactive catalyst, a lubricant, an antioxidant, etc. and used for production of polyurethane elastomers. <P>SOLUTION: In the method for producing a polyol compound comprising a polyol having 200-2,000 number-average molecular weight, a particulate thickener component in which pH obtained when dispersed in a quantity of water equal to the polyol is 4-10, a reaction catalyst and an antioxidant, the temperature of the polyol compound after formulating the particulate thickener component is controlled to ≤70°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a polyol compound, and more particularly to a method for producing a polyol compound that can be suitably used for producing a polyurethane elastomer.

  A two-component polyurethane elastomer consisting of an isocyanate component and a polyol component can be obtained by mixing these components and heat-curing them, but has excellent flexibility and resilience as a sealing material, as well as safety and hygiene. Because of its excellent properties, it is suitably used as a sealing material for metal caps (Patent Document 1).

  In polyurethane elastomers used for such sealing materials, it is necessary to blend compounding agents such as lubricants, thickeners, antioxidants, pigments, etc., and these compounding agents are generally blended in advance with a polyol component and manufactured as a polyol compound. Such a polyol compound is mixed with an isocyanate component to form a polyurethane elastomer.

JP 2003-205963 A

  However, when a polyurethane elastomer is produced using such a polyol compound, the mixing / reaction of the isocyanate component and the polyol component may not proceed smoothly, resulting in insufficient curing of the polyurethane elastomer, resulting in a satisfactory sealing material. Caused the problem that it may not be possible to form. This tendency was particularly prominent when a specific thickener component suitable for sealing material application was blended.

  Therefore, the object of the present invention is to provide a polyol compound containing a reaction catalyst, a lubricant, an antioxidant, etc., used for the production of polyurethane elastomers, even when a thickener component particularly suitable for sealing materials is blended. Another object of the present invention is to provide a method for producing a polyol compound capable of producing a polyurethane elastomer capable of exhibiting excellent sealing performance without causing insufficient curing.

According to the present invention, a polyol having a number average molecular weight of 200 to 2000, a particulate thickener component having a pH of 4 to 10 when dispersed in an equal amount of water, a reaction catalyst and an antioxidant. In the method for producing a compound, there is provided a method for producing a polyol compound, characterized in that the temperature of the polyol compound after blending the particulate thickener component is adjusted to 70 ° C. or less.
In the method for producing the polyol compound of the present invention,
1. The polyol compound contains amide and / or silicon lubricant,
2. The particulate thickener component is talc,
3. The reaction catalyst is a polymer catalyst and / or DOTDL;
4). After a part of the polyol, amide and / or silicon lubricant, reaction catalyst, and antioxidant are melt-mixed in advance, and the remaining polyol and particulate thickener component are stirred and mixed at a temperature of 120 ° C. or less. Adjusting the temperature to a temperature of 70 ° C. or lower,
Is preferred.

In the polyol compound obtained by the production method of the present invention, even when the polyurethane elastomer is prepared by mixing with the isocyanate component, there is no insufficient curing regardless of the composition of the isocyanate component, and the sealing performance is excellent. It is possible to obtain a stable polyurethane elastomer.
Moreover, according to the polyol compound obtained by the production method of the present invention, an excellent curing reaction can be obtained with a small amount of reaction catalyst.

  In the method for producing a polyol compound of the present invention, the polyol compound is a polyol having a number average molecular weight of 200 to 2000, a particulate thickener component having a pH of 4 to 10 when dispersed in an equal amount of water, The first feature is that it comprises a reaction catalyst and an antioxidant, and when preparing the compound by mixing the above components, the preparation temperature is set to a lower temperature than that of the conventional production method. The second feature is to adjust the temperature after blending the thickener component to 70 ° C. or lower.

As described above, when a polyol compound composed of the above components is used, there has been a problem that in the production of a polyurethane elastomer, the reaction between the isocyanate component and the polyol component does not proceed smoothly and the polyurethane elastomer is insufficiently cured.
As a result of investigating the cause of such problems, the present inventors have heretofore been due to the temperature at the time of preparing a polyol compound comprising the above-mentioned respective components, and the temperature at the time of such compound adjustment is the specific thickener component. It was found to be related to behavior.
That is, in the conventional method for producing a polyol compound comprising the above components, the melting point of the reaction catalyst or lubricant is used as a reference, and after these components are dissolved, the mixture is stirred and mixed at a temperature of 120 ° C. or higher. The manufacturing method of filling the container for the compound at a temperature was adopted, but the target product after mixing the specific thickener component with the temperature of stirring and mixing after each component was dissolved was 120 ° C or lower By adjusting the temperature of the polyol compound to 70 ° C. or lower, it becomes possible to produce a polyol compound that does not cause the above-described problems.

Such operational effects of the present invention are also apparent from the results of Examples described later.
That is, in a polyol compound in which each component is stirred and mixed at a temperature of 120 ° C. or less, talc as a thickening component is blended, and then the liquid temperature is lowered to 70 ° C. or less, it reacts stably with isocyanate. In contrast to the formation of polyurethane elastomers that can exhibit excellent sealing performance without causing insufficient curing (Examples 1 to 3), stirring and mixing are performed at a temperature of 120 ° C. or higher even after each component is dissolved. In the polyol compound, the liquid temperature after the blending of talc, which is a thickening component, is adjusted to 80 ° C or higher, the reaction with the isocyanate varies, resulting in insufficient curing and insufficient thickness immediately after baking. It is clear that it is difficult to obtain satisfactory sealing performance (Comparative Examples 1 and 2).

(Polyol compound)
The polyol compound of the present invention comprises a polyol having a number average molecular weight of 200 to 2000, a particulate thickener component having a pH of 4 to 10 when dispersed in an equal amount of water, a reaction catalyst, and an antioxidant. It is an essential component.

[Polyol]
As the polyol, a polymer polyol having a number average molecular weight of 200 to 2000 is used. Specific examples thereof include polypropylene glycol polyether polyol (PPG), polytetramethylene ether glycol (PTMG) and adipate polyester polyol, polycaprolactone polyester polyol, polycarbonate polyol and the like. From the viewpoint of eluate of polyurethane elastomer, PTMG and adipate polyester polyol are preferable. From the viewpoint of hydrolysis resistance, PTMG and PPG are more preferable.
It is important that the number average molecular weight is 2000 or less. If it exceeds 2000, the crystallinity becomes strong and handling becomes difficult.
In the present invention, the polyol component most preferably used for sealing materials has a hydroxyl value of 20 to 350 (mgKOH / g), preferably 100 to 350 (mgK0H / g). When the hydroxyl value is less than 20 (mgKOH / g), the resulting polyurethane elastomer is too soft and the compression set becomes too large. When it exceeds 350 (mgKOH / g), it is too hard and unsuitable as a sealing material. It is. The average number of functional groups of the polyol is preferably 2 to 3 corresponding to the average number of functional groups of the polyisocyanate component since an appropriate amount of a crosslinked structure is preferably introduced into the polyurethane elastomer.

[Particulate thickener]
Particulate thickeners include carbon black, white carbon, kaolin clay, pyrophyllite, talc, montmorillonite, sericite, calcined clay, mica, bentonite, silica sand, alumina, barium sulfate, etc., polyethylene, polypropylene , Polymer particles such as polyurethane, nylon, polyester, and acrylic, and natural organic particles such as wood powder and fruit shell powder. Talc can be particularly preferably used.
As the thickener, it is important that the pH when dispersed in an equal amount of water is in the range of 4 to 10, particularly 5 to 9, and the pH when the thickener is dispersed in water is less than 4. In such a case, the urethanization reaction between the polyisocyanate and the polyol is inhibited, and the curability becomes extremely inferior. Moreover, when pH exceeds 10, since the urethanation reaction of polyisocyanate and a polyol is inhibited, it is not preferable.
Furthermore, since the thickener component having a pH of 4 to 10 is inactive, it does not affect the formation of urethane bonds due to the reaction of the polyisocyanate and the polyol. There is no adverse effect. In addition, since the particulate thickener also has a function as a filler, it also has an advantage of improving the shape retention of the molded product.

As the particle diameter of the thickener, those having a central particle diameter of 1 to 500 μm, particularly 5 to 100 μm are preferable. When the particle diameter is smaller than the above range or larger than the above range, thickening at a high temperature of 80 ° C. or higher is insufficient, and the moldability becomes poor.
The thickener component is preferably used in the polyol compound in an amount of 5 to 50% by weight, in particular 10 to 30% by weight. When it falls below the above range, a mold flow occurs at a high temperature, and when it exceeds the above range, the viscosity at room temperature becomes high, and in either case, the moldability becomes poor.
The water content of the thickener is preferably 5% by weight or less, particularly 2% by weight or less. If the water content exceeds the above range, water and isocyanate groups react with each other during baking to generate carbon dioxide gas. Occurs and becomes abnormally foamed, impairing performance such as sealing performance.

[Reaction catalyst]
As reaction catalysts, dibutyltin dilaurate, dioctyltin dilaurate (DOTDL), triethylamine, bismuth 2-ethylhexanoic acid, diazabicycloundecene, dimethyltin bis (isooctylglycolate), monomethyltin tris (isooctylglycol) Rate), di (n-octyl) tin S, S′-bisisooctyl mercaptoacetate, di (n-octyl) tin malate polymer, and the like.
Among them, a polymer catalyst such as di (n-octyl) tin malate polymer and / or DOTDL can be preferably used.
The reaction catalyst is preferably contained in the polyol compound in an amount of 10 to 500 ppm, particularly 50 to 300 ppm.

[Antioxidant]
As the antioxidant, a hindered phenol-based antioxidant can be preferably used. Specifically, 3-methyl-2,6-tert-butyl-phenol, tetrakis [methylene-3 (3 ′, 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] methane (manufactured by Ciba Geigy, Irganox 1010).
The antioxidant is preferably blended in the polyol compound in an amount of 0.01 to 0.5% by weight, particularly 0.05 to 0.3% by weight.

[Lubricant]
When the polyol compound of the present invention is used for a sealing material comprising a polyurethane elastomer, it is preferable to add a lubricant.
Examples of the lubricant include hydrocarbon-based lubricants such as liquid paraffin, paraffin wax, and polyethylene wax, amide-based lubricants such as stearic acid amide, oleic acid amide, and erucic acid amide, and silicon-based lubricants. A silicon-based lubricant can be suitably used.
The lubricant is preferably contained in the polyol compound in an amount of 1 to 20% by weight, particularly 5 to 15% by weight.

  In addition to the above additives, the polyol compound of the present invention includes fillers, colorants, flame retardants, UV absorbers, light stabilizers, electrical insulation improvers, fungicides that are commonly used in polyurethane resins. Additives such as silicone surfactants, metal salts of organic acids, waxes derived from organic acids, metal oxides, metal hydroxides, internal mold release agents, reinforcing agents, foaming agents as required Can also be blended.

(Preparation of polyol compound)
In the method for producing a polyol compound of the present invention, a polyol compound is prepared by adding and mixing the above-described polyol, particulate thickener component, reaction catalyst, lubricant and antioxidant components in the following steps.
First, after dissolving the polyol, a reaction catalyst, an antioxidant and, if necessary, a lubricant are added to a part of the polyol to be used, and the reaction catalyst and the lubricant are completely dissolved in the polyol, preferably 100 to 130 ° C. In the temperature range, a polyol is dissolved and mixed in advance to prepare a reaction catalyst, a lubricant and an antioxidant-containing polyol. At this time, it is important to maintain the temperature after the reaction catalyst and the lubricant are dissolved at 120 ° C. or less, and the temperature is preferably adjusted to a temperature range of 100 to 120 ° C. Thus, by previously dissolving the reaction catalyst, lubricant and antioxidant in the polyol, it is possible to maintain the temperature of the subsequent stirring and mixing with the remaining polyol at a low temperature of 70 ° C. or lower.

The remaining polyol, pigment, particulate thickener, foaming agent, and other compounding agents are blended with the reaction catalyst, lubricant and antioxidant-blended polyol prepared in advance, and mixed with stirring. In the present invention, it is important to maintain the mixing temperature at 70 ° C. or lower at this time, and the temperature is preferably adjusted to a temperature range of 70 to 50 ° C.
In addition, when blending the foaming agent, it is preferable to temporarily stop stirring in order to prevent foaming of the liquid.
Next, defoaming of the compound liquid is performed. The defoaming operation can be performed by a conventionally known means. Preferably, the inside of the container is depressurized and vacuum degassed while stirring and mixing the compound liquid.
When defoaming, the liquid temperature is adjusted so that the liquid temperature does not exceed 70 ° C by stirring. Thereafter, the pressure is returned to normal pressure, and the container is filled with the compound solution.
In the present invention, the temperature of 70 ° C. or lower is the liquid temperature of the polyol compound after the particulate thickener is added and mixed. Specifically, the particulate thickener is added and mixed, and the particulate thickener is added. It is the temperature of the polyol compound measured from when the agent was sufficiently dispersed until filling the container as a product.

  In the method for producing a polyol compound of the present invention, the temperature during stirring and mixing is maintained at a temperature of 120 ° C. or lower in any of the preparation of the reaction catalyst and antioxidant-blended polyol and polyol compound, and the particulate thickener is used. After blending, it is important to adjust to a temperature of 70 ° C. or lower. For this reason, it is important to provide a temperature adjusting mechanism in the container used for mixing and stirring. Specifically, it is preferable to use a mixing container in which a heating mechanism such as an electric heater or a steam jacket and a cooling mechanism such as a cooling water jacket are mounted on the outer wall of the mixing container, and heating, cooling, and cooling are appropriately performed. The temperature is adjusted accordingly.

  In the method for producing a polyol compound of the present invention, the preparation of the reaction catalyst and antioxidant-containing polyol described above, the mixing and stirring of the polyol compound, and the defoaming operation can be performed in one mixing tank, and the efficiency of the production equipment And space saving can be achieved.

(Preparation of polyol)
PTG-1000SN (hydroxyl value 112, average functional group number = 2) 66 parts, adipate polyester glycol P-1010 (hydroxyl value 112, average functional group number = 2) 21 parts by weight, adipate polyester triol (hydroxyl value 336, average functional group) Base number = 3) 13 parts by weight were mixed to prepare a polyol having a number average molecular weight of 890.
The hydroxyl value of the polyol was measured according to the method of JIS-K1601.

(Example 1)
In addition to 160 kg of the polyol prepared by the above-described method, 0.155 kg (250 ppm / polyol) of di (n-octyl) tin maleate polymer KS-1010A-1 manufactured by Kyodo Yakuhin as a reaction catalyst, and Irganox 1010 as an antioxidant. 24 kg was added and mixed and stirred. Next, 20 kg of oleic acid amide and 20 kg of erucic acid amide were added and dissolved by heating at 120 ° C. The heating tank was charged with a mixing tank that can be sealed.
The mixing tank is equipped with a heating and cooling device, a high-speed shaft with a high-speed blade at the center of the tank, and a low-speed blade along the inner wall of the tank, and a concentric twin-screw mixer (CDMG-1000) manufactured by Inoue Mfg. Co., Ltd. It was used.
At the time of charging, the mixing tank was heated so that precipitation of amide and the like did not occur due to a decrease in the liquid temperature.

Thereafter, the remaining polyol (460 kg), titanium oxide (20 kg) and talc (150 kg) were added, and the mixture was stirred and mixed with a high-speed blade and a low-speed blade along the inner wall of the tank.
Moreover, immediately after talc addition mixing, the mixing tank was cooled and the compound liquid temperature was lowered. The temperature of the compound liquid after stirring and mixing was 68 ° C.
Subsequently, 15 kg of silicon oil and 4.5 kg of thermally expandable hollow particle EXPANSEL 092DU120 manufactured by EXPANSEL were added, and the cooling water was adjusted so that the liquid temperature did not exceed 70 ° C., and the mixture was stirred and mixed for 20 minutes. The compound solution temperature was 65 ° C.
Thereafter, the mixing tank was sealed, and the inside of the tank was evacuated with a vacuum defoaming machine to perform defoaming. The defoamed container was filled into an 18-liter can and sealed. The temperature of the compound liquid at the time of filling was 64 ° C.

(Example 2)
In the same manner as in Example 1, a catalyst, an antioxidant and an amide were added to a polyol, heated and dissolved at 120 ° C., and then each material was added and mixed sequentially in a mixing tank. At that time, the cooling was adjusted so that the temperature of the compound liquid after the addition of talc was 60 ° C. Similarly, the compound was produced while adjusting the cooling of the mixing tank. The liquid temperature of the compound at the time of filling the container was 52 ° C.

(Example 3)
A compound was produced in the same manner as in Example 2, except that 0.93 kg (150 ppm / polyol) of di (n-octyl) tin maleate polymer KS-1010A-1 manufactured by Kyodo Yakuhin was used as the reaction catalyst. The liquid temperature of the compound after talc addition and mixing was 58 ° C., and the liquid temperature of the compound at the time of filling the container was 48 ° C.

(Comparative Example 1)
In the same manner as in Example 1, a catalyst, an antioxidant and an amide were added to a polyol, heated and dissolved at 120 ° C., and then each material was added and mixed sequentially in a mixing tank. At that time, the mixing tank was heated (heated), and the mixture was stirred to produce a compound.
The liquid temperature of the compound after talc addition and mixing was 85 ° C., and the liquid temperature of the compound at the time of filling was 79 ° C.

(Comparative Example 2)
A compound was produced in the same manner as in Comparative Example 1 except that 0.31 kg (500 ppm / polyol) of di (n-octyl) tin malate polymer KS-1010A-1 manufactured by Kyodo Yakuhin was used as the reaction catalyst. The liquid temperature of the compound after talc addition and mixing was 83 ° C., and the liquid temperature of the compound at the time of filling was 78 ° C.

(Evaluation methods)
Polyisocyanate component: 78.9 parts by weight of hexamethylene diisocyanate (HDI) and 21.1 parts by weight of 1,3-butylene glycol are charged in a reaction vessel and reacted at 70 ° C. for 5 hours to obtain a number average molecular weight of 430 and an average number of functional groups = 2 A polyisocyanate having an isocyanate content of 19.7% by mass was prepared.
The polyisocyanate group content was measured according to the method of JIS-K7301.

1. Curability test (evaluation of degree of curing)
Mix quickly so that the component ratio between the hydroxyl value of the polyol compound and the polyisocyanate group content is 1.07. Using an applicator with a width of 40 mm and an opening of 1.0 mm, the width 100 × length 100 × thickness 0. It apply | coated to the aluminum plate of 25 mm, and it baked with the hot air circulation type electric oven of 225 degreeC, and created the test piece. Immediately after removing the test piece from the oven, the surface was scratched with a spatula to examine the cured state.
No surface scraping: ○
With surface scraping: ×

2. Flowability test (Evaluation of smoothness during lid creation)
Mix quickly so that the component ratio of the hydroxyl value of the polyol compound to the polyisocyanate group content is 1.07. Mixture 0 from the top 30 mm of an aluminum plate having a width of 50 × length of 250 × thickness of 0.25 mm 0.5 g was dropped and heated in a hot air circulation type electric oven at 140 ° C. for 40 seconds to prepare a test piece. The test piece was taken out of the oven, the aluminum plate was quickly and vertically suspended for 15 seconds, and the distance through which the mixed solution flowed was measured.

3. Lid preparation A groove formed on the inner periphery of a 53 mm diameter twist-off cap with a lining device, which was quickly mixed so that the component ratio of the hydroxyl value of the polyol compound to the polyisocyanate group content was 1.07 Lining was performed on the (bottle mouth seal) so that the coating amount was 1.2 g and the thickness was 1.2 ± 0.2 mm.
Then, it was immediately baked under the condition of 225 ° C. × 40 seconds to form a twist-off cap and a cap sealing material, and the cap sealing material formed on the lid was evaluated.

Claims (5)

In a method for producing a polyol compound comprising a polyol having a number average molecular weight of 200 to 2000, a particulate thickener component having a pH of 4 to 10 when dispersed in an equal amount of water, a reaction catalyst and an antioxidant,
A method for producing a polyol compound, characterized in that the temperature of the polyol compound after blending the particulate thickener component is adjusted to 70 ° C or lower.   The method for producing a polyol compound according to claim 1, wherein the polyol compound contains an amide and / or a silicon lubricant.   The method for producing a polyol compound according to claim 1 or 2, wherein the particulate thickener component is talc.   The method for producing a polyol compound according to any one of claims 1 to 3, wherein the reaction catalyst is a polymer catalyst and / or DOTDL.   A part of the polyol, amide and / or silicon lubricant, reaction catalyst, and antioxidant are melt-mixed in advance, and the remaining polyol and the particulate thickener component are stirred and mixed at a temperature of 120 ° C. or less. The method for producing a polyol compound according to any one of claims 2 to 4, wherein the temperature is adjusted to a temperature of 70 ° C or lower.