JPH07206958A - Production of hot-press molded form and composition therefor - Google Patents

Abstract

PURPOSE:To obtain a hot-press molded form excellent in mechanical properties with shortened molding time, by molding a blend of a specific binder and an actualizing catalyst for polyurethane and other component(s) in the absence of moisture, etc. CONSTITUTION:This hot-press molded form can be obtained by molding, in the virtual absence of moisture and organic solvent, a blend of an actualizing catalyst for polyurethanes (e.g. N,N'-diphenyl-p-phenylenediamine) (and resin powder or granules such as of nonexpandable polyurethane resin containing a polyol like polyether polyol) and a binder such as a nonionic urethane prepolymer having 3-15wt.% of isocyanate group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hot press molded product and a composition for a molded product. More specifically, it relates to a method for producing a composite material useful for recycling waste plastic and a molding composition suitable for the method.

[0002]

2. Description of the Related Art The use of waste materials such as waste rubber and plastics has been attracting attention from the viewpoint of resource saving and pollution-free. Various methods have been proposed for converting waste materials into practically valuable moldings, but they are sufficient in terms of molding method, mechanical properties of moldings, cost, and necessity of pretreatment of waste materials. There is no. For example, a method for producing a molded article by heating and compressing lignocellulose impregnated with a polyisocyanate-based binder in the presence of a heat-activatable catalyst (JP-A-60-55016), containing cement or asbestos To produce polyurea concrete from the mixture of the water dispersion and the ionic group-containing polyisocyanate (JP-A-50-87192), scrap of flexible polyurethane foam and polyisocyanate are reacted in the presence of water vapor. Method for manufacturing cushion material (Japanese Patent Publication No. 54-40590)
Is proposed. However, JP-A-60-550
In the method described in Japanese Patent Publication No. 16, the strict process control is required for impregnating the lignocellulose with the polyisocyanate that easily reacts with moisture in the air, and the urethane prepolymer has a relatively high viscosity. Therefore, there is a problem in that it is difficult to impregnate, a special catalyst is required, and that molding conditions are restricted depending on the catalyst. In the method described in Japanese Patent Laid-Open No. 50-87192,
There is a problem in the water resistance and mechanical strength of the molded product, and in the method described in JP-B-54-40590, there is a problem in that the waste material and the binder are poorly integrated, and in addition, an organic solvent is substantially required. is there.

[0003]

The present invention solves the above-mentioned problems, shortens the molding time, and allows molding with simple manufacturing equipment.
An object of the present invention is to provide a method for producing a molded product having good physical properties and a composition for a molded product.

[0004]

In view of the above circumstances, the inventors of the present invention have conducted extensive studies on a binder and a plastic molding method using the binder, and as a result, have achieved the present invention. That is,
According to the present invention, in producing a heat-pressing molded product composed of a binder, which is a manifestation catalyst for polyurethane or resin powder or granules containing the catalyst and a polyol, and a binder, 3 to 15 as a binder is used. weight%
For producing a hot press molded article using the urethane prepolymer having an isocyanate group, and a resin powder containing a blocked urethane prepolymer containing 3 to 15% by weight of a latent isocyanate group and a revealing catalyst for polyurethane The present invention relates to a composition for a molded product, which comprises a body or granules, and a method for producing a molded product by hot pressing the composition.

The resin used in the present invention may be either a thermoplastic or thermosetting resin. Examples of the thermoplastic resin include styrene / butadiene resin, acrylic / butadiene / styrene resin, neoprene resin, and polyolefin resin such as EPDM. Examples of the thermosetting resin include urethane resin, acrylic resin, polyester resin, and epoxy resin. Of these, preferred are polyolefin resins and urethane resins. Urethane resin is more preferable.

The resin may be in the form of powder or particles, and its particle size is not particularly limited, but is usually 3 mm or less, preferably 0.01 to 3 mm.

In the present invention, the manifestation catalyst is an activated catalyst that promotes the reaction between an isocyanate compound and an active hydrogen compound without requiring heat, unlike a heat activation type catalyst. Examples thereof include compounds and organometallic compounds.

Examples of amine compounds include primary amines, secondary amines, tertiary amines [triethylenediamine, etc.] and salts thereof. Specific examples of these include diphenylamine derivatives [N, N'-diphenyl-p-phenylenediamine, etc.], hindered amines, hexamethylenetetramine, N-butyraldehyde aniline, guanidine, thiourea, amide (hexyl-2-benzothiazoli). Rusulfenamide), triethylenediamine,
Examples thereof include bis- (2-dimethylaminoethyl) ether, tris (dimethylaminopropyl) hexahydro-S-triazine, tetramethylpropylenediamine, N-ethylmorpholine and diazabicycloalkene.

Examples of the organometallic compound include tin compounds and lead compounds. Specific examples thereof include tin octylate, dibutyltin dilaurate and lead octylate.

Preferred of these catalysts are amine compounds and tin compounds.

The content of the catalyst is not particularly limited, but is usually 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the resin powder or granules. This range provides a suitable cure time.

The urethane prepolymer used as a binder in the present invention is obtained by reacting a polyol and a polyisocyanate stoichiometrically in excess of the polyisocyanate.

As the polyol, a polyether polyol containing 2 active hydrogens, a polyester polyol,
Examples thereof include polybutadiene glycol, polycarbonate polyol and siloxane bond-containing polyol. Of these, preferred are polyether polyols and polyester polyols.

Examples of the polyether polyol include dihydric alcohols [ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, etc.], dihydric phenols [pyrroganol, hydroquinone. Etc.], dicarboxylic acids [succinic acid, adipic acid, sebacic acid, maleic acid, dimer acid, phthalic acid, terephthalic acid, trimellitic acid, etc.] and a compound having a structure in which an alkylene oxide is blocked or randomly added.

As the alkylene oxide added to the above dihydric alcohols and dihydric phenols, ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), butylene oxide (hereinafter BO).
Abbreviated), tetrahydrofuran (hereinafter abbreviated as THF) and the like. These may be used alone or in combination of two or more. Of these alkylene oxides, EO, PO and THF are preferred.

The preferred polyether polyol is an alkylene oxide adduct of a dihydric alcohol.

As the polyester polyol, a condensed polyester polyol or lactone [ε-obtained by reacting with the dihydric alcohol or dicarboxylic acid described above is used.
Caprolactone and the like] and polyester polyols obtained by ring-opening polymerization.

Two or more kinds of the same or different kinds of polyol may be used in combination.

The molecular weight of the polyol is usually 400 to 10,000, preferably 1,000 to 8.0, from the viewpoint of the impregnation property into resin powder or granules and the mechanical properties of the molded product.
00.

The polyisocyanate to be reacted with the polyol is an aromatic polyisocyanate having 6 to 20 carbon atoms (excluding carbons in the NCO group) (for example, 2,4- and / or 2,6-tolylene diisocyanate (TDI)). , Crude TDI,
2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), crude MDI [crude diaminophenylmethane {condensation product of formaldehyde with aromatic amine (aniline) or a mixture thereof: diaminodiphenylmethane and a small amount ( (For example, 5 to 20% by weight) a mixture with a trifunctional or higher polyamine} phosgene compound: polyaryl polyisocyanate (PAPI) and the like]; aliphatic polyisocyanate having 2 to 18 carbon atoms (eg hexamethylene diisocyanate, lysine diisocyanate and the like) ); Carbon number
4 to 15 alicyclic polyisocyanates (for example, isophorone diisocyanate, dicyclohexylmethane diisocyanate); araliphatic polyisocyanates having 8 to 15 carbon atoms (for example, xylylene diisocyanate); and modified products of these polyisocyanates (urethane groups, Carbodiimide group, allophanate group, urea group,
Buret group, uretdione group, uretonimine group,
Modified products containing isocyanurate groups and oxazolidone groups); and polyisocyanates other than the above described in JP-A No. 61-76517; and mixtures of two or more thereof. Of these, commercially readily available polyisocyanates such as 2,4- and 2,6-TD
I, and mixtures of these isomers, crude TDI, 4,4'- and 2,4'-MDI, and mixtures of these isomers, PAPI, also known as crude MDI, and derived from these polyisocyanates Modified polyisocyanates containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a buret group, and an isocyanurate group.

In the present invention, the N of the urethane prepolymer is
CO% is 3 to 15% by weight, preferably 5 to 15%. Outside this range, good workability and mechanical properties of the molded product cannot be obtained.

The method of incorporating the manifesting catalyst or the mixture of the catalyst and the polyol into the resin powder or granules may be a conventional method. For example, it can be obtained by mixing the revealing catalyst or the mixture of the catalyst and the polyol with resin powder or granules under normal pressure or under reduced pressure. Mixing under reduced pressure enhances impregnation into the resin powder or granules and is therefore preferred.

Although the content of the catalyst is not particularly limited, it is usually
It is 0.01 to 5% by weight with respect to the resin. Outside this range, the curing time is too short or, conversely, too long to obtain an appropriate curing time.

In the present invention, as the urethane prepolymer used for the blocked urethane prepolymer, those mentioned above can be used.

As blocking agents, oximes [acetoxime, butanone oxime, cyclohexanone oxime, etc.], phenols [phenol, cresol, p-toluenethiol, etc.], alcohols [2,2,2-trifluoroethanol, etc.] , Amines [di-n-butylamine, N-hydroxyphthalamide, etc.] and other compounds [caprolactam, acetohydroxyamic acid, p-toluenesulfoamide, thioglycolic acid, acetone phenylhydrazone, etc.]. Of these, oximes are preferable.

The compounding ratio (weight) of resin powder or granules and binder is usually resin powder or granules / binder = 1.
The amount is 00 parts / 5 to 30 parts, preferably 100 parts / 5 to 20 parts. Outside this range, good strength of the molded product cannot be obtained.

The molding temperature is not particularly limited, but is usually 100.
C. or higher, preferably 120 to 200.degree. The molding pressure is not particularly limited, but is usually 50 Kg / cm 2 G or more, preferably 100 to 200 Kg / cm 2 G. The molding time is not particularly limited, but is usually within 10 minutes, preferably 1
~ 5 minutes.

[0028]

The present invention will be further described below with reference to examples, but the present invention is not limited thereto.

Resin 1: N, N'-diphenyl-p-phenylenediamine was impregnated with 0.1% by weight and had an average particle size of 0.
5mm ground styrene butadiene rubber. Resin 2: 0.3% by weight of triethylenediamine is impregnated into ground urethane rubber having an average particle size of 0.5 mm. Urethane prepolymer A: propylene glycol with EO
/ PO = 8/2 (weight ratio) is a reaction product of a polyol having a hydroxyl value of 56 and metaphenylene diisocyanate obtained by addition polymerization of a mixture, and having an NCO% of 6%. Urethane prepolymer B: PO in propylene glycol
Is a reaction product of a polyol having a hydroxyl value of 56 and metaphenylene diisocyanate, and has an NCO% of 1
1%. Urethane prepolymer C: Urethane prepolymer B in which all the terminal isocyanate groups are blocked with acetoxime. Polyol A: A polymer having a molecular weight of 400 by adding PO to propylene glycol.

Example 1 100 parts of Resin 1 and 12 parts of Urethane Prepolymer A were uniformly mixed and filled in a mold having a mold temperature of 150 ° C., then 150 K
The mold was released after pressurizing at g / cm 2 G for 3 minutes. The mechanical strength of the molded product is 121.2Kg / cm2 in tensile strength and 65 in elongation.
%, And the tear strength was 65.2 Kg / cm.

Example 2 100 parts of resin 2 and 12 parts of urethane prepolymer A were uniformly mixed and charged in a mold having a mold temperature of 150 ° C.
The mold was released after pressurizing at g / cm 2 G for 3 minutes. The mechanical strength of the molded product is tensile strength 133.2Kg / cm2, elongation 86
%, And the tear strength was 73.2 Kg / cm.

Example 3 100 parts of resin 2 and 10 parts of urethane prepolymer B were uniformly mixed and charged in a mold having a mold temperature of 150 ° C., then 150 K
The mold was released after pressurizing at g / cm 2 G for 3 minutes. The mechanical strength of the molded product is 164.5Kg / cm2 in tensile strength and 80 in elongation.
%, And the tear strength was 85.6 Kg / cm.

Example 4 100 parts of resin 2 and 15 parts of urethane prepolymer C were uniformly mixed and filled in a mold having a mold temperature of 150 ° C., then 150 K
The mold was released after pressurizing at g / cm 2 G for 5 minutes. The mechanical strength of the molded product is tensile strength 123.1 Kg / cm2, elongation 65
%, And the tear strength was 75.2 Kg / cm.

Comparative Example 1 15 parts of urethane prepolymer B and 2,100 parts of resin were thoroughly mixed. To this mixture was added diethylenetriamine 0.
An attempt was made to add and mix 1 part, and to inject into a mold, but the viscosity increased rapidly, and it was not possible to inject uniformly.

COMPARATIVE EXAMPLE 2 15 parts of urethane prepolymer B, 0.1 part of diethylenetriamine and 7.9 parts of polyol A were premixed and then tried to mix with 2 parts of resin 2, which rapidly thickened and therefore became homogeneous. It could not be cast into the mold because it did not mix.

[0036]

EFFECTS OF THE INVENTION In the method for producing a hot press molded product of the present invention, the molding time can be shortened, and molding can be carried out by a simple one-component casting machine. Further, the molded body is excellent in mechanical properties because it is composited in a mesh shape. Therefore, it is particularly useful for recycling waste plastics.

Claims (6)

[Claims] 1. A method for producing a heat-pressing molded article comprising a surface-exposing catalyst for polyurethane or resin powder or particles containing the catalyst and a polyol and a binder and substantially without the presence of water and an organic solvent. A method for producing a hot press molded article using a urethane prepolymer having 3 to 15% by weight of an isocyanate group as a binder. 2. The method according to claim 1, wherein the urethane prepolymer is nonionic. 3. The method according to claim 1, wherein the resin is a non-foamed polyurethane resin. 4. The production method according to claim 1, wherein the manifestation catalyst or the catalyst and the polyol are attached to the surface or inside of the resin powder or granules. 5. The number of latent isocyanate groups is 3 to.
A composition for a molded body, which comprises a resin powder or granules containing a blocked urethane prepolymer containing 15% by weight and a revealing catalyst for polyurethane. 6. A method for producing a molded article, which comprises hot pressing the composition according to claim 5.