JPH10330529A - Method for producing composite resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a composite resin composition in which a composite resin composition obtained by kneading a crosslinked polyurethane resin and a non-reactive resin has improved stainability and thermal stability. A method for producing a composite resin composition obtained by kneading a cross-linked polyurethane resin, a non-reactive resin, and a compound that reacts with a hydrolysis product of the polyurethane resin at a temperature equal to or higher than the hydrolysis temperature of the cross-linked polyurethane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a composite resin composition comprising a crosslinked polyurethane resin, a non-reactive resin, and a compound which reacts with a hydrolysis product of the polyurethane resin.

[0002]

2. Description of the Related Art In recent years, with the increasing interest in environmental issues, the creation of an environment-friendly society has been demanded, and the recycling of waste products for the purpose of reducing the burden on the environment and effectively using resources has been studied. Is underway. Various studies have been made also on automobiles. In particular, resin bumpers are large external parts, and material recycling is being actively studied.

Here, a polypropylene resin or a polyurethane resin is used for the resin bumper. The former is a thermoplastic resin that can be remelted, and it is easy to recycle waste materials and the like. Is a thermosetting resin that forms an insoluble / infusible molecular skeleton by a crosslinking reaction,
It cannot be recycled without any treatment.

[0004] As a method of recycling the polyurethane resin bumper, a method of decomposing the resin by chemical treatment such as glycolysis, aminolysis or hydrolysis and returning the same to the original material (chemical recycling), burning the resin to generate heat energy Method of recovery (thermal recycling), cutting, cutting and pulverizing resin as filling, filling material, leveling material, sound absorbing material, vibration damping material, etc., or as a substitute for rubber parts by adding a binder and pressing and compression molding The method used (material recycling) is an example.

[0005] In material recycling in which a waste material of a polyurethane resin bumper is mixed into a resin material or the like to obtain a recycled component, in order to prevent problems such as deterioration of material properties and surface quality due to poor dispersion of additives, the mixing property of both materials is reduced. It is important to increase. As such a method, Japanese Patent Application No. Hei 8-11
No. 4895 discloses a technique of blending waste hard or semi-hard polyurethane resin into a thermoplastic resin or the like to form a composite resin composition having excellent physical properties.

[0006]

However, the composite resin composition obtained by kneading the non-reactive resin and the cross-linked polyurethane resin in the prior art lacks reactivity with the finely dispersed cross-linked urethane resin, so that plasticization is difficult. Since the urethane resin is dispersed in that state, the oligomer component and the low molecular weight component generated by the cross-linking cleavage cause problems of contamination and thermal stability.

The present invention has been made in view of the above-mentioned circumstances, and a compound capable of reacting and immobilizing and stabilizing a cross-linked urethane resin by adding a compound capable of reacting with an oligomer component or the like generated by cross-linking cleavage. It is an object to provide a method for producing a resin composition.

[0008]

Means for Solving the Problems The process for producing a composite resin composition of the present invention comprises a compound which reacts with a crosslinked polyurethane resin, a non-reactive resin and a hydrolysis product of the polyurethane resin (hereinafter referred to as a reactive compound). ) Is a method for producing a composite resin composition of a crosslinked polyurethane resin and a non-reactive resin obtained by kneading at a temperature equal to or higher than the hydrolysis temperature of the polyurethane resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The composite resin composition of the present invention is produced by kneading a crosslinked polyurethane resin containing water, a non-reactive resin and a reactive compound at a temperature not lower than the hydrolysis temperature of the crosslinked polyurethane resin. Is done. The crosslinked polyurethane resin of the present invention comprises a hydroxy compound, an isocyanate compound, and a crosslinking agent as main components, and is formed by RIM molding or R-RIM.
The target material is semi-rigid or hard polyurethane resin obtained by reaction injection molding such as molding, and it is not necessary to be limited to waste materials generated in the manufacturing process and waste materials collected from the market, new materials may be used, New materials and waste materials may be mixed.

The hydroxy compound constituting the crosslinked polyurethane resin of the present invention is not particularly limited. Examples of the polyester compound include hydroxypolyesters produced from polybasic acids such as phthalic acid, adipic acid, and maleic acid and hydroxyl compounds such as glycols, trimethylolpropane, hexanetriol, glycerin, and pentaerythritol. Further, poly (oxypropylene ether) polyols, polyether polyols such as poly (oxyethylene-propylene ether) polyol, acrylic polyols, castor oil derivatives, tall oil derivatives, polypropylene glycol,
Examples include polyethylene glycol and other compounds having two or more hydroxyl groups.

The hydroxy compounds may be used alone or in combination of two or more. Further, it may be linear or branched, and may have a bifunctional or higher hydroxyl group. The isocyanate compound constituting the crosslinked polyurethane resin of the present invention includes, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,
Examples thereof include aliphatic isocyanates such as 4,4'-diphenylmethane diisocyanate, and derivatives such as trimers of toluene diisocyanate and urea polymers of toluene diisocyanate.

These isocyanate compounds may be used alone or in combination of two or more. Further, it may have a bifunctional or more isocyanate group. The isocyanate compound is not particularly limited, but preferably aromatic isocyanate is suitable for reaction injection molding. Examples of the crosslinking agent include amines such as hexamethylenediamine, 4,4'-diaminodiphenylmethane, and diethyltoluenediamine. These compounds may be used alone or in combination of two or more.

The hydrolysis product of the crosslinked polyurethane resin can be formed under the hydrolysis conditions described below, and is obtained by maintaining the crosslinked polyurethane resin containing water at a temperature higher than the hydrolysis temperature and lower than the liquefaction temperature. In this case, it can be obtained by treating the crosslinked polyurethane resin alone, and can also be obtained by treating in the presence of a thermoplastic resin.

The non-reactive resin is a resin having no functional group capable of reacting with an active group generated by crosslinking or hydrolysis of a cross-linked polyurethane resin. No, but melting temperature is 300
It is desirable to use a resin having a temperature of not more than ℃. This is because if left at a temperature of 310 ° C. or more for a long time, the polyurethane resin is decomposed and liquefied.

Examples of the non-reactive resin include olefin resins such as polypropylene resin and polyethylene resin,
A thermoplastic polyurethane resin is exemplified. There is no particular limitation on the ratio between the crosslinked polyurethane resin and the non-reactive resin. The kneading at a temperature higher than the melting temperature is a treatment at a temperature higher than a temperature at which a normal thermoplastic resin can be kneaded.

The reactive compound is a compound having a functional group capable of reacting with an active group generated by hydrolysis of a crosslinked polyurethane resin, and is preferably an acid anhydride or an isocyanate compound. The addition amount is appropriately determined depending on the composition of the crosslinked polyurethane and the like. The hydrolysis conditions of the cross-linked polyurethane resin are such that the cross-linked polyurethane resin is heated and treated at a temperature higher than the temperature at which the cross-linked polyurethane resin undergoes hydrolysis.
It is important that the crosslinked polyurethane resin absorbs moisture appropriately. It is preferable that the moisture absorption is at least 0.1% or more after being not subjected to the drying treatment before the treatment. The upper limit of the moisture absorption is 10%. 10% moisture absorption
If it exceeds 300, the treatment is difficult due to steam generated during kneading, which is not preferable. The water content is more preferably in the range of 0.5 to 6%.

Further, the crosslinked polyurethane resin does not need to contain water, as long as it is in the presence of water, and water may be added to the extent that it absorbs 10% or less of moisture during the hydrolysis treatment.
As a guide for controlling the amount of water, it is sufficient that the amount is more than about 0.1%. Further, a compound containing an active hydrogen or an organometallic compound may be added for the purpose of promoting the decomposition reaction,
Further, other additives may be added within a range not to impair the present invention.

In the present invention, the crosslinked point of the crosslinked polyurethane resin is cut with heat and moisture. Therefore, unless the water is volatilized during the treatment, the desired treated product cannot be obtained. The treatment temperature is desirably not less than the hydrolysis temperature of the crosslinked polyurethane resin and not more than the liquefaction temperature. The processing time is determined as appropriate because it varies depending on the composition of the crosslinked polyurethane resin, the processing temperature, the structure of the processing apparatus, and the like.

The kneading device for kneading the compound capable of reacting with the crosslinked polyurethane resin, the non-reactive resin and the hydrolysis product may be any kneading device provided with a heating means. For example, a flat roll, an extruder, a kneader or the like may be used. I can give it. Also,
The non-reactive resins may be used alone or in combination of two or more. In particular, a screw-type extruder is preferable as a processing device because it can suppress volatilization of water and can perform continuous processing.

In the case of processing a large component such as a bumper, it is desirable to coarsely pulverize the large-sized component in advance to have an average particle size of more than 1 mm and 50 mm or less. Even if a member having a particle size larger than 1 mm is used, it can be dispersed as fine particles in the resin. The composite resin composition produced by the production method according to the present invention comprises a crosslinked polyurethane resin obtained by kneading a crosslinked polyurethane resin, a non-reactive resin, and a reactive compound at a temperature not lower than the hydrolysis temperature of the crosslinked polyurethane resin. It is a composite resin composition with a reactive resin.

The crosslinked polyurethane resin contains a hydroxyl compound (hydroxyl group-containing compound), an isocyanate compound and a crosslinking agent as main components, and is formed by RIM molding or R-RIM.
A semi-hard or hard urethane resin obtained by reaction injection molding such as molding, and has a moisture absorption of 0.1% by weight or more
0% by weight or less. Further, as the non-reactive resin,
An olefin-based thermoplastic resin is used, and an acid anhydride or an isocyanate compound is used as the reactive compound.

[0022]

EXAMPLE As an example of the treatment of a crosslinked polyurethane resin, R-
A case where a polyurethane resin bumper manufactured by RIM molding is used will be described. As a monomer material of the polyurethane resin bumper material, polypropylene glycol, diethyltoluenediamine, and 4,4′-diphenylmethane diisocyanate were used, and a reinforcing material filled with a single fiber whisker of potassium titanate was used. This is RIM
After molding to a thickness of 3mm with a molding machine, about 5m with a hammer mill
m to give a crosslinked urethane resin. The crosslinked urethane resin is in a state of natural moisture absorption, and the amount of moisture absorption is 0.8% by weight.

As the non-reactive resin, a homo-type polypropylene resin (H501) manufactured by Sumitomo Chemical Co., Ltd. was used. Hexamethylene diisocyanate (H
DI), methylene diisocyanate (MDI), maleic anhydride (MA), phthalic anhydride (PA), 4-methyltetrahydrophthalic anhydride (THPA), phenol resin oligomer, phenol novolak resin oligomer (P
H), dodecyl succinic anhydride (DDSA) was used. Further, an epoxy resin (Epicoat 828 (DGEB
A)), an epoxy-modified polyethylene resin (Nippon Petrochemical's Recpal RA3150 (RA)), an acid-modified polypropylene resin (Sanyo Chemical's Umex 1010 (YU))
Was also used.

As a processing apparatus, a twin screw reaction extruder TEX-30α (L / D = 45.5) manufactured by Nippon Steel Works was used. The extrusion processing conditions were a resin temperature of 200 ° C. or 260 ° C. and a screw rotation speed of 500 rpm. The residence time of the material was about 2 minutes. (Preparation of Sample) A crosslinked urethane resin, a non-reactive resin, and a reactive compound were kneaded at a composition ratio shown in Table 1 to prepare a composite resin composition sample. Here, in Examples 1 to 4, in the twin-screw extrusion processing, a liquid addition pump was connected to the latter half of the processing apparatus, and the reactive compound was added in the middle. Also,
Examples 5 to 20 are samples in which a reactive compound was simultaneously treated with a urethane resin and a non-reactive resin, in which the reactive compound and the amount added were changed. Further, Examples 21 to 23 are samples prepared by preparing the sample of Comparative Example 1, adding the reactive compound again, and performing the simultaneous treatment with a twin-screw extruder. Comparative Examples 1 and 2 are samples to which no reactive compound was added.

[0025]

[Table 1]

(Evaluation of Contamination) 10 g of sample pellets obtained by the extrusion treatment are weighed in a glass container and sealed with a glass plate. Half the height of the container, immersed in an oil bath at 80 ° C, measured the amount of sample adhered to the glass plate after 20 hours and visually judged the fogging state of the glass plate to determine the contamination. It is shown in Table 2. In addition, ○ △ ×
The criterion for the evaluation is that ○ indicates no adhesion, Δ indicates remarkable improvement,
X indicates that slight adhesion was observed, and x indicates that large amount of adhesion was observed.

[0027]

[Table 2]

Examples 1 to 4 are examples in which an isocyanate compound is added after the crosslinked urethane resin is hydrolyzed, and no contamination is observed even when the composition ratio of the composite resin is changed. In Examples 5 to 7, the amount of the reactive compound added was as small as 0.5 part by weight, so that slight adhesion to the glass plate was observed. However, the amount of the reactive compound clearly decreased due to the addition of the reactive compound. I understand.

Examples 14 to 20 demonstrate that the reactive compound
This is an example in which an acid anhydride other than the above or another resin such as an epoxy resin is used. Also in this case, a decrease in the amount of adhesion is observed, and the effect of adding the reactive compound is understood. In Examples 21 to 23, the resin prepared in Comparative Example 1 was reacted with a reactive compound, and these samples did not show any contamination. This indicates that the sample also reacts with the resin molded sample.

In Table 2, when the examples of the present invention and the comparative examples are compared with respect to the stainability, the comparative examples in which the reactive compound was not added had high stainability, whereas the reactive compound was added. It can be seen that in the examples of the present invention, the contamination is considerably reduced. (Evaluation of Thermal Stability) Test pieces of the composite resin compositions of Examples 11 to 13 and Comparative Example 1 were molded by injection molding. These samples are subjected to a tensile test and an Izod impact test before and after standing at 100 ° C. for 1000 hours, and a retention ratio with respect to an initial value is determined. The retention is shown in Table 3 and the thermal stability is evaluated.

[0031]

[Table 3]

In Table 3, Examples 11 to 13 of the present invention are shown.
In Comparative Example 1 and Comparative Example 1, there is a large difference between the retention of tensile elongation and the retention of Izod impact value, and the present invention with the addition of the reactive compound has greatly improved thermal stability. Also, comparing the examples 11 to 13, it can be seen that the order of higher thermal stability is HDI>MDI> MA.

Further, from Tables 2 and 3, the effect of the reactive compound in the present invention was found to be the effect of isocyanate compound> acid anhydride> epoxy compound> other compound.

[0034]

According to the composite resin composition of the present invention, when the crosslinked polyurethane resin, the non-reactive resin, and the reactive compound are kneaded under hydrolysis conditions, the bonding points of the crosslinked polyurethane resin are cut by hydrolysis and softened. Then, they are made finer and more uniform with the non-reactive resin by the elasticity. Also, by reacting a reactive group generated by hydrolysis with a reactive compound,
The oligomer component and the like generated by the hydrolysis can be re-reacted and immobilized to improve the contamination and the thermal stability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 101/00 C08L 101/00 // B29K 105: 26

Claims (1)

[Claims] 1. A crosslinked polyurethane resin characterized by kneading a crosslinked polyurethane resin, a non-reactive resin, and a compound which reacts with a hydrolysis product of the polyurethane resin at a temperature not lower than the hydrolysis temperature of the crosslinked polyurethane resin. A method for producing a composite resin composition with a non-reactive resin.