JPH07216139A - Rubber chip composition - Google Patents

Abstract

PURPOSE:To obtain a compsn. which can reduce the cycle time without reducing the pot life of a premix and gives an elastomer with excellent mechanical strengths by compounding rubber chips, an NCO-terminated urethane resin, and a water-contg. solid substance. CONSTITUTION:This compsn. contains rubber chips, an NCO-terminated urethane resin, and a water-contg. solid substance (e.g. a metal oxide, hydroxide, or salt contg. water of crystallization, or a hydrophilic polymer which can take in water). The compsn. can greatly reduce the cycle time without reducing the pot life of a premix, improving production efficiency and reducing cost. The resulting elastomer, having high tensile strength, tear strength, and elongation, can provide durable sheets, mats, etc.

Description

Detailed Description of the Invention

[0001]

[Industrial applications]

The present invention relates to a resin composition used for paving materials and the like.

[0003]

2. Description of the Related Art Urethane resins having an isocyanate group at the end are widely used as auxiliary materials in the fields of construction and civil engineering because they firmly adhere to various rubber powders, wood chips, sand and the like. In particular, an elastic body made by bonding and curing rubber chips with urethane resin has excellent walking and running sensations and is relatively inexpensive, so golf courses, tennis courts, jogging courses, athletic fields, parks, It is widely used as a paving material for schoolyards. Such an elastic body is used when a rubber chip and urethane resin are mixed at the construction site and rolling is performed with a trowel or a heat roller, or when the rubber chip and urethane resin are preheated by a heat molding press or a heat molding roll. There are cases where elastic bodies produced in factories are laid at construction sites. In the case of factory production, a urethane resin is mixed with rubber chips in a granular shape, a flat shape, a fibrous shape, etc., and if necessary, a coloring agent, a catalyst, etc. are added, and a heat molding press or a thermoforming roll is used.
It is manufactured as a mat, an interlocking block, and the like. Since such production is usually carried out under curing conditions of 140 to 170 ° C. for 15 to 30 minutes, it takes a long cycle time of 20 to 40 minutes from injection into the mold to demolding, resulting in high production efficiency. It is quite bad, it causes a cost increase, and it often fails to meet the construction schedule. Therefore, it is desired to improve the productivity. In order to increase productivity, it is necessary to shorten the time required for curing. Generally, a catalyst is used or the curing temperature is raised to increase the reactivity and shorten the cycle time. It is under consideration. However, in the former case, the pot life when the rubber chip and urethane resin are mixed becomes extremely short, and therefore the work of injecting into the mold becomes difficult. Further, the latter has a problem that the urethane resin is thermally deteriorated, the obtained elastic body is yellowed, or the physical properties are deteriorated.

[0004]

As described above, in the prior art, when the elastic body made of the rubber chip and the urethane resin is manufactured by the hot molding press or the thermoforming roll, the production efficiency is considerably low and the cycle time is shortened. In particular, it is highly desired to shorten the time required for curing.

[0005]

In order to produce an elastic body composed of a rubber chip and a urethane resin by using a heat molding press or a thermoforming roll, the present inventors shorten the cycle time, especially the thermosetting time. As a result of diligent research on shortening of the above, it was found that this problem can be remarkably improved, and the present invention has been completed. That is, the present invention provides (a)
The present invention relates to a resin composition containing a rubber chip, (b) a urethane resin having an isocyanate group at the terminal, and (c) a water-containing solid substance, a production method, and its use. The rubber chips used in the present invention include those obtained by crushing and classifying waste materials of industrial rubber products such as vehicle tires, window frame gaskets and belt conveyors. Further, for example, natural rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), pyridine-butadiene rubber (PBR), butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), styrene -One or more of isoprene rubber (SIR), butyl rubber (IIR), ethylene-propylene rubber (EPR), ethylene-propylenediene rubber (EPDM), urethane rubber (UR), etc., color pigments, vulcanizing agents, reinforcements Agent, filler, antiaging agent, etc. are added, and the mixture is kneaded and vulcanized by a conventional means such as a double roll, Banbury mixer, kneader or extruder, and then pulverized. Classified rubber chips, or rubber chips whose surface is coated with a coloring paint after crushing the rubber (JP-A-2-10) 828 and JP-Hei 2-123180), and also like.

The shape of the rubber chip thus obtained is, for example, powdery, granular, flat or fibrous, and can be appropriately selected depending on the use of the elastic body to be obtained. In the case of a fibrous rubber chip, a cross section having a substantially circular shape with a diameter of 0.5 to 5 mm and a length of 3 to 30 mm is used. These can also be used by appropriately mixing them. Fibrous colored rubber chips are preferably used. The urethane resin having an isocyanate group at the terminal used in the present invention is a urethane prepolymer having at least one isocyanate group at the terminal, and usually has an organic polyisocyanate and two or more active hydrogen groups. Polio
Or polyamine or the like. Examples of the organic polyisocyanate include tolylene diisocyanate (TDI), diphenylmethane-4,4'-diisocyanate (MDI), diphenylmethane-2,4 '.
-Diisocyanate (2,4'-MDI), naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'-biphenylene diisocyanate (T
ODI), liquid diphenylmethane diisocyanate liquefied by various conventionally known methods described in JP-B-38-4576, etc.
(Liquid MDI), crude tolylene diisocyanate (crude TDI), aromatic polyisocyanate such as polymethylene polyphenyl polyisocyanate (crude MDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI)
Aroaliphatic polyisocyanate such as hexamethylene diisocyanate (HDI), isophorone diisocyanate
(IPDI), bis (isocyanatomethyl) cyclohexane (H ₆ XDI), dicyclohexylmethane-
Aliphatic or alicyclic polyisocyanate such as 4,4′-diisocyanate (H ₁₂ MDI) and the like can be mentioned, and these are used as one kind or as a mixture of two or more kinds. From the viewpoint of curability and physical properties, tolylene diisocyanate and diphenylmethane diisocyanate are preferably used.

Examples of the polyol having two or more active hydrogen groups include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexane glycol and neopentyl glycol. Low molecular weight polyols such as glycols, trimethylolpropane, and triols such as glycerin, poly (oxypropylene) polyol, poly (oxyethylene) polyol, poly (oxyethylenepropylene) polyol, poly (oxytetramethylene) glycol, Poly (caprolactone) polyol, polybutadiene polyol, poly (butylene carbonate) polyol, poly (hexamethylene carbonate) polyol, poly (ethylene adipate) polyol, poly (propene N'ajipeto) polyol, poly (butylene adipate) polyol, and poly (hexane adipate) polyol, and the like high molecular weight polyols such as epoxy polyol. These are used as one kind or as a mixture of two or more kinds. Particularly preferred are poly (oxypropylene) polyols, poly (oxyethylene propylene) polyols, poly (oxytetramethylene) glycols, polybutadiene polyols, etc., which usually have an average molecular weight of 400-600.
It is preferably 0 and has an average number of functional groups of 2 to 6.
As the polyamine having two or more active hydrogen groups, for example, ethylenediamine, hexamethylenediamine, isophoronediamine, 4,4′-diphenylmethanediamine, 2,4-tolylenediamine, 2,6-tolylenediamine, 3 , 5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene,
Examples thereof include diamines such as 1,3,5-triethyl-2,6-diaminobenzene, polyamines such as ethylenetriamine, triethylenetetramine, and poly (oxyalkylene) polyamine.

The urethane resin having an isocyanate group at the terminal used in the present invention is generally produced by reacting the above organic polyisocyanate with the above polyol or polyamine by a known method. For example, the reaction temperature is about 40 to 130 ° C. and the reaction time is about 4 to 10 at an equivalent ratio (NCO / H) of the isocyanate group and the active hydrogen group of 1.2 to 10.
It can be produced by reacting for a time. Usually, the isocyanate group content of the synthesized prepolymer is 1 to 15%.
And 2.5 to 10% is particularly suitable as the prepolymer of the present invention. Moreover, the viscosity is 1,000 to 50,000.
cps (25 ° C), especially from the standpoint of workability, 2.00
0 to 10,000 cps (25 ° C) is suitable. The urethane resin may be added with conventionally known catalysts, solvents, plasticizers, pigments, stabilizers, reaction retarders and the like. Examples of the catalyst include amine catalysts such as triethylamine, tripropylamine, N-methylmorpholine, N-octadecylmorpholine, triethanolamine, and triethylenediamine, such as tin acetate and tin octylate.
Tin oleate, tin laurate, dibutyltin diacetate
And organic metal catalysts such as dibutyltin dilaurate, dibutyltin dichloride, dibutyltin oxide, lead octylate, lead naphthenate, nickel naphthenate, and cobalt octylate. Examples of the solvent include
Aromatic solvents such as toluene, ethylbenzene, xylene, chlorobenzene, dichlorobenzene, ethyl acetate,
Aliphatic solvents such as butyl acetate, methyl cellocerve, ethyl cellosolve, ethyl carbitol, butyl carbitol and the like can be mentioned.

Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, dinonyl phthalate and phthalate. Phthalate plasticizers such as diisodecyl acid salt, ditridecyl phthalate, dibutylbenzyl phthalate, dicyclohexyl phthalate, etc., such as dioctyl adipate, diisodecyl adipate, dioctyl azelate, dibutyl sebacate, dioctyl sebacate and the like. Basic acid ester-based plasticizers, for example, glycol ester-based plasticizers such as diethylene glycol dibenzoate and dipentaerythritol hexaester,
Examples thereof include phosphate ester-based plasticizers such as tricresyl phosphate and trioctyl phosphate, and epoxy-based plasticizers such as epoxidized soybean oil, butyl epoxystearate, and octyl epoxystearate. As the pigment,
For example, calcium carbonate, barium carbonate, barium sulfate, talc, barite, anhydrite, magnesium carbonate,
Extender pigments such as magnesium hydroxide, mica, zinc white, lead white, lithopone and zinc sulfide, for example, titanium oxide, carbon black, iron oxide, lead chromate, chromium oxide, ultramarine, cobalt blue, cyanine blue, cyanine green , Lake red, quinacridone red, and the like. Examples of the stabilizer include phenolic stabilizers such as benzoyl chloride and dibutylhydroxytoluene, for example, 2,6-di-t-butyl-4-hydroxytoluene, for example, bis (2,2,6,6).
6-Tetramethyl-4-piperidyl) sebacate, bis- (1,2,6,6-pentamethyl-4-piperidyl)
Amine stabilizers such as sebacate, for example, 2- (2'-
Hydroxy-5'-methylphenyl) benzotriazo-
Examples thereof include benzotriazole-based stabilizers such as phenol, and phosphorus-based stabilizers such as triphenyl phosphite.

As the reaction retarder, ethyl chlorocarbonate, isopropyl chlorocarbonate, isobutyl chlorocarbonate,
Ethylhexyl chlorocarbonate, n-propyl chlorocarbonate,
N-Butyl chlorocarbonate, hexyl chlorocarbonate, ethoxyethyl chlorocarbonate, sec-butyl chlorocarbonate, benzyl chlorocarbonate, phenyl chlorocarbonate, butoxyethyl chlorocarbonate, allyl chlorocarbonate, chlorocarbonate 2,2.2-
Halogenocarbonic acid esters such as trichloroethyl (Japanese Patent Application No. 03-007073), caproic acid chloride, stearic acid chloride, adipic acid chloride, phthalic acid chloride, naphthalenedicarboxylic acid chloride, trimellitic acid trichloride, biphenylcarboxylic acid chloride, phenyl Examples thereof include organic carboxylic acid halogenites such as acetic acid chloride, naphthalene acetic acid chloride, and tripropionic acid chloride (Japanese Patent Publication No. 3-65372). The amount ratio of these added is, for example, urethane resin.
0.01 to 1 part by weight of catalyst and 1 to 100 parts by weight of solvent
10 parts by weight, plasticizer 1 to 30 parts by weight, pigment 0.5 to 10
Weight part, stabilizer 0.02 to 1 weight part, reaction retarder 0.5
It is in the range of 10 parts by weight. The water-containing solid substance used in the present invention is a solid at room temperature, has no water on the surface, and releases water at the heating temperature during curing,
It can be anything. For example, hydrates, hydrate compounds and the like can be mentioned. Examples of the water-containing material include inorganic compounds that adsorb water in voids and channel structures, such as activated carbon and zeolite.

Examples of the water-containing compound include metal oxides, metal hydroxides and metal salts containing water of crystallization, for example,
Iron sulfate ₍₂ FeSO4 · 7H O), barium hydroxide (Ba
_{(OH) 2 · 8H 2 O} ), calcium sulfate (CaSO ₄ · 2
H ₂ O), copper sulfate _{(CuSO 4 · 5H 2 O)} , magnesium sulphate _{(MgSO 4 · 7H 2 O)} , magnesium phosphate _{((Mg) 3 (PO 4} ) 2 · 4H 2 O), magnesium silicate ( _{mg 2 Si 3 O 8 · 5H} 2 O), sodium silicate (Na
₂ SiO ₃ · 9H ₂ O), copper acetate (Cu (CH ₃ COO) ₂ ·
2H ₂ O), sodium acetate (CH ₃ COONa ・ 3H ₂
O), sodium carbonate (Na ₂ CO ₃ · 12H ₂ O), sodium phosphate (Na ₃ PO ₄ · 12H ₂ O), sodium hydrogen phosphate (Na ₂ HPO ₄ · 12H ₂ O), sodium sulfate (Na ₂ SO ₄ · 10H ₂ O), sodium borate (Na ₂ B ₄ O ₇ · 10H ₂ O) and the like. As the water-containing compound, a hydrophilic polymer capable of taking in water, for example, polyacrylamide, polyvinylpyrrolidone, polyurethane, cellulose derivative, starch derivative and the like can also be used. These hydrates and hydrates are powdery or granular and retain water stably at room temperature, and the heating temperature at the time of curing, for example, 40 to 250 ° C.,
Preferably, a substance that releases water at 60 to 170 ° C. is preferable, and the water-containing material is zeolite, and the water-containing compound is barium hydroxide (Ba (OH) ₂ .8H ₂ O), sodium borate (Na ₂ B _4). O ₇ · 10H ₂ O) and sodium carbonate (Na ₂ CO ₃ · 12H ₂ O) are preferably used. The mixing ratio of the rubber chip, the urethane resin and the water-containing solid substance of the present invention is such that in the urethane resin, the rubber chip 100
It is 5 to 30 parts by weight with respect to parts by weight, and normally, the range of 5 to 20 parts by weight is preferable when the shape of the rubber chip is granular or flat, and the range of 10 to 30 parts by weight is preferable when it is fibrous. The water-containing solid substance is added in an amount of 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts of the rubber chips. Further, the ratio of the water-containing solid substance to the urethane resin is such that the equivalent ratio (NCO / OH) of water released at the heating temperature to the terminal isocyanate group of the urethane resin is 0.2 to
It is preferable to mix it so as to be 5, especially 0.6 to 2.0.

These rubber chips, urethane resin and water-containing solid substance may be mixed in advance before molding, or may be mixed at the time of molding. The elastic body of the present invention is manufactured, for example, as follows. Put the rubber chips in a mortar mixer, disper, kneader, etc. and stir it, or put it in a container and stir it with an electric mixer while adding a predetermined amount of water-containing solid substance in advance. The water-containing solid substances of are added separately and mixed until the whole shows a wet state. Fill this mixture into a mold of the specified shape,
A molded product is obtained by curing with a hot press heated to 0 ° C. for 1 to 60 minutes. The elastic body manufactured by such a method has excellent mechanical strength and is used as a pavement material for golf courses, tennis courts, jogging courses, athletic fields, parks, schoolyards and the like.

[0012]

According to the method for producing a resin composition and an elastic body of the present invention, the cycle time can be remarkably shortened without shortening the pot life of the premix, so that the production efficiency can be improved and the cost can be reduced. Further, since the obtained elastic body has high tensile strength and tear strength, and also has a high elongation rate, it is possible to provide a sheet, mat, interlocking block and the like having excellent durability.

[0013]

EXAMPLES The present invention will be specifically described below with reference to reference examples, examples and comparative examples, but the present invention is not limited to these examples. All "parts" in Reference Examples, Examples and Comparative Examples represent parts by weight. Reference Example 1 (Production of Urethane Resin Having Isocyanate Group at Terminal) Diphenylmethane-4,4′-diisocyanate 269
Parts, molecular weight 4,000 poly (oxyethylene propylene) diol (Takeda Pharmaceutical Co., Ltd. ACTCOL MF-1
2) 416 parts, poly (oxypropylene) diol having a molecular weight of 2,000 (ACTCOL 21 manufactured by Takeda Pharmaceutical Co., Ltd.)
-56) 162 parts, poly (oxypropylene) triol having a molecular weight of 1,000 (Actcole 32-160, manufactured by Takeda Pharmaceutical Co., Ltd.) 57 parts, liquid diphenylmethane polyisocyanate (manufactured by Takeda Bardish Urethane Industry) 86 parts of luplanet MB301) was charged into a reaction apparatus, and a urethanization reaction was carried out at 70 to 80 ° C. for 6 hours under a nitrogen stream.
Furthermore, after cooling to 50 ° C or lower, benzoyl chloride is reduced to 0.
A urethane resin was obtained by adding 5 parts and 50 parts of di2-ethylhexyl phthalate. This urethane resin has a viscosity of 3,8
00 cps / 25 ° C, isocyanate group content 8.2%,
The specific gravity was 1.08.

Example 1 (Method for producing elastic body 1) 1,000 parts of fibrous colored rubber chips (Kara-Hijiki M manufactured by Takeda Pharmaceutical Co., Ltd.), urethane resin 1 obtained in Example 1
50 parts, sodium borate (Na2B4O7 / 10H2O) 4
After pre-mixing 0 parts using an electric mixer, it was filled in an aluminum mold (internal volume 300 × 150 × 20 mm),
It was heated at 160 ° C. for 7 minutes with a hot press to obtain a mat-like elastic body. Although the pot life of the premix was the same as that of the comparative example, this elastic body was sufficiently cured, and the tensile strength, tear strength, and elongation were values that were satisfactory. The measured values are shown in [Table 1]. Example 2 (Method for producing elastic body 2) 1,000 parts of fibrous colored rubber chip (Takeda Pharmaceutical Co., Ltd. Color-Hijiki M), urethane resin 1 obtained in Example 1
50 parts of barium hydroxide _{(Ba (OH) 2 · 8H} 2 O) 4
After pre-mixing 0 parts using an electric mixer, it was filled in an aluminum mold (internal volume 300 × 150 × 20 mm),
The mat-like elastic body was obtained by heating at 160 ° C. for 7 minutes with a hot press. This elastic body is sufficiently hardened, the tensile strength,
The tear strength and the elongation were both satisfactory values. The measured values are shown in [Table 1].

Example 3 (Method for producing elastic body 3) 1,000 parts of fibrous colored rubber chips (Kara-Hijiki M manufactured by Takeda Pharmaceutical Co., Ltd.), urethane resin 1 obtained in Example 1
50 parts, sodium carbonate (Na ₂ CO ₃ .12H ₂ O) 9
After pre-mixing 0 parts using an electric mixer, it was filled in an aluminum mold (internal volume 300 × 150 × 20 mm),
The mat-like elastic body was obtained by heating at 160 ° C. for 7 minutes with a hot press. This elastic body is sufficiently hardened, the tensile strength,
The tear strength and the elongation were both satisfactory values. The measured values are shown in [Table 1]. Example 4 (Manufacturing method of elastic body 4) 1,000 parts of fibrous colored rubber chip (Kara-Hijiki M manufactured by Takeda Pharmaceutical Co., Ltd.), urethane resin 1 obtained in Example 1
After mixing 50 parts and 90 parts of zeolite (WR Grace's silosib A4) saturated with water and vapor-phase dried in advance by using an electric mixer, an aluminum mold (internal volume 300 ×
150 × 20 mm) and heated at 160 ° C. for 7 minutes with a hot press to obtain a mat-like elastic body. The elastic body was sufficiently cured, and the tensile strength, tear strength, and elongation were values that were satisfactory. The measured values are shown in [Table 1].

Comparative Example 1 1,000 parts of a fibrous colored rubber chip (Kara-Hijiki M, manufactured by Takeda Pharmaceutical Co., Ltd.), the urethane resin 1 obtained in Example 1
After mixing 50 parts in advance by using an electric mixer, it was filled in an aluminum mold (internal volume 300 × 150 × 20 mm) and heated at 160 ° C. for 7 minutes by a hot press. But,
The curing reaction did not proceed sufficiently, the surface of the mat-like elastic body was tacky, and the tensile strength, tear strength, and elongation were all low values. The measured values are shown in [Table 1]. Comparative Example 2 1,000 parts of a fibrous colored rubber chip (Kara-Hijiki M, manufactured by Takeda Pharmaceutical Co., Ltd.), the urethane resin 1 obtained in Example 1
After mixing 50 parts in advance by using an electric mixer, the mixture was filled in an aluminum mold (internal volume 300 × 150 × 20 mm) and heated at 200 ° C. for 7 minutes by a hot press. But,
Degradation, which is considered to be caused by heat, was observed, the surface of the mat-like elastic body turned yellow, and the tear strength and the elongation were low. The measured values are shown in [Table 1]. Comparative Example 3 1,000 parts of a fibrous colored rubber chip (Kara-Hijiki M, manufactured by Takeda Pharmaceutical Co., Ltd.), the urethane resin 1 obtained in Example 1
50 parts of dibutyl tin dilaurate and 0.5 parts of dibutyl tin dilaurate were mixed in advance with an electric mixer, and then an aluminum mold (internal volume 3
00 × 150 × 20 mm) and heat-pressed to 16
It was heated at 0 ° C. for 7 minutes to obtain a mat-like elastic body. This elastic body was almost cured, and the tensile strength, tear strength, and elongation were all reasonable values. However, the pot life before filling the formwork was extremely short. The measured values are shown in [Table 1].

[Table 1]

Claims (8)

[Claims] 1. (a) a rubber chip, (b) a urethane resin having an isocyanate group at the end,
And (c) a resin composition containing a water-containing solid substance. 2. The resin composition according to claim 1, wherein the water-containing solid substance is a water-containing compound. 3. The resin composition according to claim 2, wherein the hydrous compound is a metal oxide containing crystal water, a metal hydroxide containing crystal water, or a salt thereof. 4. The resin composition according to claim 1, wherein the water-containing solid substance is a water-containing substance. 5. The resin composition according to claim 4, wherein the hydrous material is zeolite. 6. A method for producing an elastic body, which comprises curing a resin composition containing (a) a rubber chip, (b) a resin having an isocyanate group at an end, and (c) a water-containing solid substance. 7. An elastic body obtained by curing the resin composition according to claim 1. 8. The elastic body according to claim 7, wherein the elastic body is a paving material.