Patent Application
20100024977
1) Field of the Invention
This invention relates to an industrial adhesive, particularly relates to a method for adhering woody product with amylum and polymeric macromolecule material as adhesive.
2) Description of Prior Art
In the present art, adhesive made from amylum is usually used for adhering paper product, so, its viscidity is poor that is difficult to adhere product requiring higher viscidity, such as woody product of furniture.
Objective of this invention is to provide a method for adhering woody product with amylum and polymeric macromolecule material as adhesive so as to overcome disadvantage in current art, said method can improve adhesive strength of woody product so far.
This invention is to provide a method for adhering woody product or adornment with polymeric adhesive as adhesive, wherein polymeric adhesive is composed of amylum and polymeric macromolecule material, the method to prepare adhesive includes following steps: first modify amylum and polymeric macromolecule material, then put such modified amylum and polymeric macromolecule material into vessel under 20°-100° C., but the best temperature is 45-65° C., for graft polymerization so as to prepare polymeric adhesive and steps to further modify amylum are as follows:
(1) Oxidative modification of amylum: the purpose is to oxidize parts of OH in amylum molecule into COOH, it is allowed to oxidize it on group of C2-C6 by selection, oxidation is done in alkali amylum liquor with 6-14 PH values, dosage of oxidant is 0.8%-10%, and temperature of alkali liquor is 30° C.-70° C., wherein aldehyde group is corrosion resistant and carboxyl can strengthen adhesive strength of wood fiber;
(2) Pasted modification of amylum: it is done in alkali liquor. As a matter of fact, pasting is to modify the surplus OH in amylum molecule after oxidation; the method is to keep adding proper alkali liquor so that OH in amylum molecule become St-ONa, at this moment, glue in the reaction system become thick, viscidity is increased thereof; besides, alkali liquor is added at rate of 1-15%, or PH values are between 7 and 20;
(3) Ether modification of amylum indicates that certain hydroxyl in amylum molecule is combined into another type of amylum derivative with one hydroxyl in hydroxyl compound through oxygen atom; modifying agent added during ether modification is of acid or epoxy chloropropane; acid or epoxy chloropropane in glue under temperature of 30° C. -90° C., but the best temperature is 50° C.-65° C., reacts with amylum to produce ether amylum derivative, and acid or epoxy chloropropane is added at rate of 1-15%, so that its viscidity and tenacity will be promoted, it is eligible for corrosion resistance, water resistance and adhesive strength are also strengthened so far; (4) Cross-linking modification: carbamide added in glue is able to crosslink amylum molecule, in glue at temperature of 40° C. -85° C., but the best temperature is 50° C. -65° C., carbamide shrinks with aldehyde group in amylum molecule or aldehyde produced during oxidation to produce certain high polymer, carbamide is added at rate of 1-10% that improves viscidity and strength of glue;
Above said polymeric macromolecule modification also include following steps: emulsify and copolymerize the dissolved PVA or PVAC, namely, decrease temperature of the dissolved PVA or PVAC to 50° C. -120° C., but the best temperature is 60° C. -80° C., then, add emulsifying agent and initiating agent to emulsify or copolymerize it with proper VAC or PA, so that the linked PVA colloid produces scattered particle latex to reduce viscidity but speed up fluidity. Volumes of initiating agent and VAC are 1-15% and 3-15% respectively;
Furthermore, following steps are also included for graft polymerization of above modified amylum and polymeric macromolecule: polymerize the modified amylum and polymeric macromolecule material in vessel at 20° C.-100° C., but the best temperature is 50° C.-65° C., to produce high quality natural plant amylum adhesive. Steps to adhere woody product with the prepared adhesive as described above are as follows:
coat above described adhesive on surface of two pieces of woody product at temperature of −10° C. -50° C., and then press down another surface of two pieces of woody product at pressure of 5 kg, it takes 5-25min to air under normal temperature and gets hardened within 24 h. Said adhesive can adhere any kind of woody product; product adhered with adhesive in accordance with this invention will not crack even soaked in water for 48 h and boiled in water of 63° C. for 3 h, shear and dry strength of standard sample can reach 5-14 MPa, its wet strength is 2-7 MPa.
Above said woody product is one of following products: woody furniture, fabric furniture, kitchen furniture, veneer, density fiber board, flakeboard;
Above said adornment includes one of following products: internal wall paint, paint stucco, internal wall ceramic tiles, wall paper, wall cloth, carpet and leather;
Above said adhesive is also applicable to correction liquor.
Method of the invention can adhere any kind of woody product, such as woody furniture, fabric furniture, kitchen furniture, veneer, density fiber board, flakeboard; product adhered with adhesive in accordance with this invention will not crack even soaked in water for 48 h and boiled in water of 63° C. for 3 h, shear and dry strength of standard sample can reach 5-14 MPa, its wet strength is 2-7 MPa, besides, it is also applicable to internal wall paint, paint stucco, internal wall ceramic tiles, wall paper, wall cloth, carpet and leather;
This invention provides a method for adhering woody product or adornment with polymeric adhesive as adhesive, wherein polymeric adhesive is composed of amylum and polymeric macromolecule material, the method to prepare adhesive includes following steps: first modify amylum and polymeric macromolecule material; then put such modified amylum and polymeric macromolecule material into vessel under 40°-80° C. for graft polymerization so as to prepare polymeric adhesive, amylum is modified in three-level steps as follows:
One or two or three steps of following three-level steps can be used for modification, it is allowed to use one or several steps according to purpose or situation using adhesive, if no serious requirement for viscidity strength, one or two steps can be used for modification, if the requirement is serious, the three-level steps shall be used for modification, sequence of said three-level modification step is changeable, and now, the operating flow of said three-level modification steps are described as follows:
Principle of three-level modification steps is that C1- C6 in amylum molecule can produce different chemical reaction on group, it is measured that hydroxide in C2,C3 and C6 can produce chemical reaction, this is why amylum molecule can be modified, a known amylum molecule contents 600-6000 dextrose molecule, the modified amylum glue prepared with single method is a modified and non-modified mixed amylum glue; thus, we can confirm that the surplus original amylum modified with single method can be modified further by adding other agents, this is the foundation and background of three-level modification theory.
(1) Oxidative modification of amylum: the purpose is to oxidize parts of OH in amylum molecule into COOH, it is allowed to oxidize it on group of C2- C6 by selection, oxidation is done in alkali amylum liquor with 6-14 PH values, dosage of oxidant is 0.8%-10%, and temperature of alkali amylum liquor is 30° C. -100° C., but the best temperature is 40° C.-55° C., wherein aldehyde group is corrosion resistant and carboxyl can strengthen adhesive strength of wood fiber;
(2) Pasted modification of amylum: it is done in alkali liquor. As a matter of fact, pasting is to modify the surplus OH in amylum molecule after oxidation; the method is to keep adding proper alkali amylum liquor so that OH in amylum molecule become St-ONa, at this moment, glue in the reaction system become thick, viscidity is increased thereof; besides, alkali liquor is added at rate of 1-15%; or PH values reach 7-20, temperature of alkali atnylum liquor is 30° C.- 100° C., but the best temperature is 50° C.-65° C.;
(3) Ether modification of amylum indicates that certain hydroxyl in amylum molecule is combined into another type of amylum derivative with one hydroxyl in hydroxyl compound through oxygen atom; modifying agent added during ether modification is of acid or epoxy chloropropane; acid or epoxy chloropropane in glue under temperature of 30° C.-70° C. reacts with amylum to produce ether amylum derivative, and acid or epoxy chloropropane is added at rate of 1-15%, so that its viscidity and tenacity will be promoted, it is eligible for corrosion resistance, water resistance and adhesive strength arc also strengthened so far.
(4) Cross-linking modification: carbamide added in glue is able to crosslink amylum molecule, in glue at temperature of 40° C.-85° C., but the best temperature is 50° C.-65° C., carbamide shrinks with aldehyde group in amylum molecule or aldehyde produced during oxidation to produce certain high polymer, carbamide is added at rate of 1-10% that improves viscidity and strength of glue;
above said polymeric macromolecule modification also include following steps: emulsify and copolymerize the dissolved PVA or PVAC, namely, decrease temperature of the dissolved PVA or PVAC to 50° C. -100° C., but the best temperature is 65° C.-85° C., then, add emulsifying agent and initiating agent to emulsify or copolymerize it with proper VAC or PA, so that the linked PVA colloid produces scattered particle latex to reduce viscidity but speed up fluidity. Volumes of initiating agent and VAC are 1-15% and 3-15% respectively;
Furthermore, following steps are also included for graft polymerization of above modified amylum and polymeric macromolecule: polymerize the modified amylum and polymeric macromolecule material in vessel at 20° C.-100° C., but the best temperature is 45° C.-65° C., to produce high quality natural plant amylum adhesive. Steps to adhere woody product with the prepared adhesive as described above are as follows:
coat above described adhesive on surface of two pieces of woody product at temperature of −10° C. -50° C., then press down another surface of two pieces of woody product at pressure of 5 kg, it takes 5-25 min to air under normal temperature and gets hardened within 24 h. Said adhesive can adhere any kind of woody product, product adhered with adhesive in accordance with this invention will not crack even soaked in water for 48 h and boiled in water of 63° C. for 3 h, shear and dry strength of standard sample can reach 5-14 MPa, its wet strength is 2-7 MPa.
Said adhesive is workable under temperature of −10-50° C., which can be aired at normal temperature between 5 and 25 min and get hardened within 24 h, it can adhere any kind of woody product by pressing down at pressure of over 5 kg according to the standard sample, such as woody furniture, fabric furniture, kitchen furniture, veneer, density fiber board, flakeboard, besides, product adhered with adhesive in accordance with this invention will not crack even soaked in water for 48 h and boiled in water of 63° C. for 3 h, shear and dry strength of standard sample can reach 5-14 MPa, its wet strength is 2-7 MPa, besides, it is also applicable to internal wall paint, paint stucco, internal wall ceramic tiles, wall paper, wall cloth, carpet and leather.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200510033796.1 | Mar 2005 | CN | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/CN2005/001957 | 11/18/2005 | WO | 00 | 10/1/2007 |
