Summary of the invention
The objective of the invention is at above-mentioned deficiency, providing a kind of with natural polymer---W-Gum is a main raw material, thoroughly solve formaldehyde and discharge problem, when reducing cost by a relatively large margin, really realize the starch-based aqueous macromolecule-isocyanate wood adhesive of wood adhesive greenization.
The technical scheme that realizes the object of the invention is:
Starch-based aqueous macromolecule-isocyanate wood adhesive belongs to two component adhesive, and host, solidifying agent are made by the raw material of following weight parts respectively:
Host:
Composite denaturation cornstarch emulsion 40-65 part of concentration 35%, diprotic acid esterification agent 8-15 part, polyvinyl alcohol 10-30 part, sanitas 1-3 part.
Solidifying agent:
Polymeric isocyanate 5-20 part.
The composite denaturation cornstarch emulsion of described concentration 35% is made by the raw material of following weight parts: W-Gum 25-35 part, concentration 0.3-0.5molL
-1Mineral acid 65-75 part, peroxide initiator 0.5-1.3 part, comonomer 5-7 part, sanitas 0.5-0.6 part.In the described raw material of preparation composite denaturation cornstarch emulsion, mineral acid can be hydrochloric acid, sulfuric acid or phosphoric acid; Peroxide initiator can be ammonium persulphate, Potassium Persulphate or Sodium Persulfate; Comonomer can be acrylamide or vinyl acetate between to for plastic; Sanitas is an edible sodium benzoate.The pH regulator agent of using in the preparation process is 10% sodium hydroxide or 5% hydrochloric acid.
Oxalic acid, maleic acid or dimethylene Succinic Acid that described diprotic acid esterification agent can be a concentration 30%; Described polyvinyl alcohol is the aqueous solution that polyvinyl alcohol is dissolved as concentration 8% or 12%, adds the solution behind the sodium laurylsulfonate of over dry polyvinyl alcohol amount 0.1% again; Described sanitas is an edible sodium benzoate.
Described polymeric isocyanate is 98% a polymeric isocyanate without sealing treatment.
The pH regulator agent of using in the preparation process is the sodium hydroxide of 3-5%.
The preparation method that above-mentioned each raw material is made starch-based aqueous macromolecule-isocyanate wood adhesive of the present invention is:
(1) preparation of composite denaturation cornstarch emulsion:
W-Gum and inorganic acid solution with weight part described in the preparation composite denaturation cornstarch emulsion, be mixed with the corn starch milk that concentration is 25-35%, heat temperature raising is incubated after 55-65 ℃, the peroxide initiator of the 1st adding 0.5-0.8 weight part in the W-Gum Ruzhong, stir, acid hydrolysis oxidative under 55-65 ℃ of temperature, pre-after initiation reaction 30-50 minute, adjust pH is to 6.8-7.2, get elementary acid hydrolysis oxidative cornstarch emulsion, after elementary acid hydrolysis oxidative cornstarch emulsion stablized 10-15 minute, the comonomer that slowly added described weight part in 30-40 minute carries out graft reaction, adjust pH is to 4.5-5.5, insulation reaction is after 1.5 hours under 55-65 ℃ of temperature, add the peroxide initiator of remaining 0.8-0.5 weight part the 2nd time again,, add sanitas continuing reaction under the 55-65 ℃ of temperature after 1.5 hours, adjust pH gets composite denaturation cornstarch emulsion to 6.8-7.2;
(2) preparation of starch-based aqueous macromolecule-isocyanate wood adhesive host:
With (1) gained composite modified starch emulsion of described weight part, stirring and heat temperature raising are regulated pH value 8.0-8.5 to 45-55 ℃ of insulation with pH value conditioning agent; Do not stop to stir down, in 20-40 minute, evenly add the polyvinyl alcohol water solution of described weight part; Then in 100-120 minute, every interval 10-15 minute, alternately add pH value conditioning agent and make pH rise to 9, add diprotic acid esterification agent again and make pH drop to 6, repeatable operation like this is till the diprotic acid esterification agent of described weight part exhausts; At last, add sanitas, stir after 30-50 minute, reduce to room temperature promptly;
(3) starch-based aqueous macromolecule-isocyanate wood adhesive solidifying agent: select polymeric isocyanate for use without sealing.
In preparation host process, can replenish the adding W-Gum, be not less than 35% to guarantee the host non-volatile matter.
Starch-based aqueous macromolecule-isocyanate wood adhesive of the present invention can be made I type, the II type wood adhesive of different compression shear strengths.The wood adhesive that is mixed with different types of varieties such as the I class is boiled repeatedly, II class Hot water immersion, II class normality after host, solidifying agent can being mixed by different ratios is in use used.
It is that main raw material substitutes synthetic resins manufacturing wood adhesive that outstanding feature of the present invention is with the natural polymer W-Gum, because the great amount of hydroxy group that W-Gum is rich in, and be easy to form a large amount of hydrogen bonds between the hydroxyl, in the aqueous solution, form the association body with water molecules.Having improved traditional API wood adhesive glued membrane easily produces dehydration exsiccant defective on the one hand, on the other hand since in the starch part of hydroxyl and polyvinyl alcohol hydroxyl crosslinked by diprotic acid formation ester bond, starch-based aqueous macromolecule-isocyanate wood adhesive host after the modification has the character of hydro-colloid, under the room temperature with after the solidifying agent polymeric isocyanate is directly mixed, tackiness agent has stability preferably, is enough to satisfy the requirement of I type or II type adhesive technology working life.Through verification experimental verification, adopt the solidifying agent polymeric isocyanate of starch-based aqueous macromolecule-isocyanate wood adhesive need not seal and directly to use.
Another outstanding feature of the present invention also is among the preparation method, be that W-Gum is made composite denaturation cornstarch emulsion through acid hydrolysis oxidative, grafting, copolymerization and modification, under certain potential of hydrogen condition, by diprotic acid esterification agent, make starch-based aqueous macromolecule-isocyanate wood adhesive host with the polyvinyl alcohol copolymerizing and blending; Employing directly as the solidifying agent of tackiness agent of the present invention, is made the nontoxic starch-based aqueous macromolecule-isocyanate wood adhesive of two-pack without the polymeric isocyanate of sealing treatment thus.
Tackiness agent of the present invention has been contained traditional API wood adhesive, satisfies the type of six kinds such as I type, II type of different purposes.Have good physicochemical performance, can be widely used in wood (bamboo) material laminated products such as multiplying plywood, three-layer real-wood (bamboo, bamboo wood) composite floor board, multi-layer solid wood composite floor, core-board, bentwood furniture, shaving board.
It is tackiness agent that starch-based aqueous macromolecule-isocyanate wood adhesive of the present invention belongs to non-formaldehyde, compares with traditional water-thinned isocyanate adhesive, has the design uniqueness, low cost of manufacture, the active phase is long, and apparent viscosity is low, precompressed good and aging, water-fast, Good Heat-resistance, technological specification, easy and simple to handle, equipment is easy to get, non-environmental-pollution, characteristics such as easy enforcement will produce huge ecological environment benefit and economic results in society after applying.
Embodiment
Below in conjunction with embodiments of the invention and test example the present invention is further described, but the present invention is not limited to embodiment, those of ordinary skills do some modification with technical solution of the present invention, still in protection domain of the present invention.
Embodiment 1-3: the preparation of the I type starch-based aqueous macromolecule-isocyanate wood adhesive of different compression shear strengths of the present invention
The weight proportion of each raw material sees Table 1 among each embodiment.
Preparation method: (with embodiment 1 is example, and other embodiment is except that raw material consumption difference, and the preparation method is substantially the same manner as Example 1)
(1) with concentration 0.5molL
-1The 24.53kg hydrochloric acid soln add and to have in the reactor of agitator, condenser, in hydrochloric acid soln, slowly add the 13.20kg W-Gum, it is 35% corn starch milk that violent stirring is mixed with concentration, insulation behind the heat temperature raising to 55 ℃ adds the 0.07kg ammonium persulphate the 1st time in the W-Gum Ruzhong, stirs, acid hydrolysis oxidative under 55 ℃ of temperature, pre-simultaneously the initiation after 30 minutes with 10% sodium hydroxide adjust pH to 7, gets elementary acid hydrolysis oxidative cornstarch emulsion.After elementary acid hydrolysis oxidative cornstarch emulsion stablized 10 minutes, in 40 minutes, slowly add the 1.89kg acrylamide, regulate pH value to 5.5 with 10% sodium hydroxide, insulation reaction is after 1.5 hours under 55 ℃ of temperature, add the 0.11kg ammonium persulphate the 2nd time again, continuing reaction under 55 ℃ of temperature after 1.5 hours (being graft reaction totally 3 hours), add the 0.20kg edible sodium benzoate, after the physicochemical property of mensuration resultant reaches requirement, to 6.8-7.2, get the composite denaturation cornstarch emulsion 40kg of concentration 33-35% with 10% sodium hydroxide adjust pH.In preparation process, be lower than 33% as non-volatile matter, can replenish the adding W-Gum and regulate.
(2) (1) gained 40kg composite modified starch emulsion is stirred and heat temperature raising to 55 ℃ insulation, regulate pH value 8.5 with the sodium hydroxide of 3-5%; Do not stop to stir down, in 20 minutes, evenly add the 1799 type polyvinyl alcohol water solutions of 21.8kg 12%; Then in 120 minutes, every interval 10 minutes, the sodium hydroxide that alternately adds 3-5% makes pH rise to 9, adds oxalic acid again and makes pH drop to 6, and repeatable operation like this is till the oxalic acid of 8.73kg exhausts; At last, add the 0.5kg edible sodium benzoate, stir after 30 minutes, reduce to room temperature and get starch-based aqueous macromolecule-isocyanate wood adhesive host 71.03kg.
(3) take by weighing without the 7.10kg polymeric isocyanate of sealing, make the solidifying agent of starch-based aqueous macromolecule-isocyanate wood adhesive.
After host and solidifying agent mix, be mixed with I type I, the application of II class normality starch-based aqueous macromolecule-isocyanate wood adhesive.
Table 1
Embodiment 4-6: the preparation of the II type starch-based aqueous macromolecule-isocyanate wood adhesive of different compression shear strengths of the present invention
The weight proportion of each raw material sees Table 2 among each embodiment.
Table 2
Preparation method: (with embodiment 4 is example, and other embodiment is except that raw material consumption difference, and the preparation method is substantially the same manner as Example 4)
(1) with concentration 0.5molL
-1The 30.66kg hydrochloric acid soln add and to have in the reactor of agitator, condenser, in hydrochloric acid soln, slowly add the 16.50kg W-Gum, it is 35% corn starch milk that violent stirring is mixed with concentration, insulation behind the heat temperature raising to 55 ℃ adds the 0.10kg ammonium persulphate the 1st time in the W-Gum Ruzhong, stirs, acid hydrolysis oxidative under 55 ℃ of temperature, pre-simultaneously the initiation after 30 minutes with 10% sodium hydroxide adjust pH to 7, gets elementary acid hydrolysis oxidative cornstarch emulsion.After elementary acid hydrolysis oxidative cornstarch emulsion stablized 10 minutes, in 40 minutes, slowly add the 2.36kg acrylamide, regulate pH value to 5.5 with 10% sodium hydroxide, insulation reaction is after 1.5 hours under 55 ℃ of temperature, add the 0.14kg ammonium persulphate the 2nd time again, continuing reaction under 55 ℃ of temperature after 1.5 hours (being graft reaction totally 3 hours), add the 0.24kg edible sodium benzoate, after the physicochemical property of mensuration resultant reaches requirement, to 6.8-7.2, get the composite denaturation cornstarch emulsion 50kg of concentration 33-35% with 10% sodium hydroxide adjust pH.In preparation process, be lower than 33% as non-volatile matter, can replenish the adding W-Gum and regulate.
(2) (1) gained 50kg composite modified starch emulsion is stirred and heat temperature raising to 45 ℃ insulation, regulate pH value 8.5 with 3-5% sodium hydroxide; Do not stop to stir down, in 30 minutes, evenly add the 1799 type polyvinyl alcohol water solutions of 20.83kg 8%; In 120 minutes, every interval 10 minutes alternately adds 3-5% sodium hydroxide and makes pH rise to 9 then, adds oxalic acid again and makes pH drop to 6, and repeatable operation like this is till the oxalic acid of 12.50kg exhausts; At last, add the 0.5kg edible sodium benzoate, stir after 30 minutes, reduce to room temperature and get starch-based aqueous macromolecule-isocyanate wood adhesive host 83.83kg.
(3) take by weighing without the 6.71kg polymeric isocyanate of sealing, make the solidifying agent of starch-based aqueous macromolecule-isocyanate wood adhesive.
After host and solidifying agent mix, be mixed with II type I, the application of II class normality starch-based aqueous macromolecule-isocyanate wood adhesive.
More than used raw material is all selected for use among each embodiment is technical grade product, quality index reaches following requirement: W-Gum meets the GB12309-1990 requirement; Peroxide initiators such as ammonium persulphate, Potassium Persulphate, Sodium Persulfate, content is more than 98%; Comonomer such as acrylamide, vinyl acetate between to for plastic, content is more than 98%; Content of hydrochloric acid 36.5%; Sulfuric acid, phosphorus acid content 98%; Sodium hydrate content 96%; Edible sodium benzoate content 98%; Diprotic acid esterification agent such as oxalic acid, maleic acid or dimethylene Succinic Acid, content 96%; Polyvinyl alcohol is 1799 types, 2099 types, 2299 types, 2499 types or 2699 types, purity 99%; Polymeric isocyanate, purity 98%, NCO content 30.5%.
Test example 1: the performance comparison test of starch-based aqueous macromolecule-isocyanate wood adhesive of the present invention
For verifying beneficial effect of the present invention, the water-based isocyanate wood adhesive with starch-based aqueous macromolecule-isocyanate wood adhesive of the present invention and Japanese silver dollar company carries out the performance comparison test.
The water-based isocyanate wood adhesive (API) of Japan silver dollar company was succeeded in developing in 1974, its host composition is a vinylbenzene---butadiene latex, polyacrylic acid latex, vinyl-acetic ester---ethylene copolymerization emulsions, polyvinyl alcohol; Solidifying agent is mainly the masked isocyanate compound.And the nucleus of the host of tackiness agent of the present invention is a W-Gum; The polymeric isocyanate compound of solidifying agent for not sealing.
The comparative test result such as glue performance of two kinds of tackiness agent see Table 3.
Test example 2: the glue performance test of starch-based aqueous macromolecule-isocyanate wood adhesive of the present invention
Tackiness agent of the present invention is respectively applied for hot pressing such as glued board, core-board, three-layer wood composite flooring and glueds joint, and industrial experimentations such as the splicing of colding pressing such as laminated wood.All kinds of laminated products of test gained detect through national wood-based plate quality supervision and test center, and detected result sees Table 4.
Table 3
Test subject |
Tackiness agent of the present invention |
Japan silver dollar Co., Ltd. tackiness agent |
Host and solidifying agent are by the working life/gelatin viscosity after 100: 10 the mixed |
6-8h/600-1200mPa.s |
1-2h/8000-15000mPa.s |
Solidifying agent |
Do not seal utilization ratio 100% |
Sealing treatment, utilization ratio 80% |
Solidify back toxicity |
Nontoxic |
Poisonous (mainly being that VOC exceeds standard) |
Cost |
4000-6000 unit/ton |
12000-18000 unit/ton |
Raw material |
The renewable resources W-Gum |
The Nonrenewable resources oil |
Table 4
Annotate: 1. JAS, No. 920 announcement of farming, forestry, fishing portion, up-to-date revision on June 28 in 2000
Test example 3: the performance test of the starch base API wood adhesive product of the different purposes of I type of the present invention
With embodiment 1-3 gained I type starch base API wood adhesive, send Changchun Inst. of Applied Chemistry, Chinese Academy of Sciences's test, test result such as table 5.
Table 5
Test example 4: the performance test of the starch base API wood adhesive product of the different purposes of II type of the present invention
With embodiment 4-6 gained II type starch base API wood adhesive, send Changchun Inst. of Applied Chemistry, Chinese Academy of Sciences's test, test result such as table 6.
Table 6
Conclusion: show that through above-mentioned test starch-based aqueous macromolecule-isocyanate wood adhesive of the present invention is the two-pack wood adhesive, host solids content height, initial viscosity is low; Solidifying agent need not seal, and mixed glue can reach 6-8 hour working life, in the utilising efficiency that has improved solidifying agent, has reduced cost.All kinds of laminated products that adopt tackiness agent of the present invention to make, its every physicochemical property all meets or exceeds the relevant criterion requirement.Adopt natural polymer---W-Gum substitutes petroleum chemicals---synthetic resins, realized the greenization production and the application of wood adhesive,, have outstanding ecological environment benefit and economic results in society for the Sustainable development of human society provides possible.