METHOD FOR MANUFACTURE A CONCENTRATED AND STABLE LACTOSE SOLUTION, AND ITS USE PARTICULARLY FOR MANUFACTURED THERMOSETTING RESINS.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- MERIDIAN INT
- Filing Date
- 1990-07-11
- Publication Date
- 1992-01-17
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Existing methods for producing concentrated lactose solutions are prone to crystallization and phase separation due to the aldehyde function of lactose, leading to instability and inefficiencies in manufacturing processes.
The addition of a chemical compound, such as an alcohol or amine, blocks the aldehyde function of lactose, preventing crystallization and phase separation by forming a lactose derivative, which can then be used to create thermosetting resins for applications like counter-veneers and glued products.
The process stabilizes the lactose solution, allowing for efficient concentration without crystallization or phase separation, and the resulting lactose derivative can be used in manufacturing thermosetting resins for adhesive applications.
Abstract
Description
The main patent describes a process for manufacturing a a concentrated and stable solution containing a lactose derivative, derived from an aqueous solution containing lactose in the form of monohydrate, characterized in that a chemical compound capable of reacting with one of the two OH functions of lactose monohydrate. According to this invention, the chemical compound used is preferably an alcohol, transforming lactose into lactose hemiacetal, such as methanol or ethanol. Adding such a chemical compound to the lactose solution has the effect of blocking the aldehyde function lactose. The applicant thus observed that, due to this "blocking" of the aldehyde function, the lactose derivative formed was no longer likely to crystallize, in the event of concentration of the solution, nor likely to form two distinct phases. The purpose of this addition is to propose alternative chemical compounds to those described in the main patent, capable of performing the same functions. than these. Following the addition, the process for manufacturing a concentrated and stable solution containing a lactose derivative is characterized in that one adds to the solution one amine. The preferred amines, according to the present addition, are urea and melamine. Amines have the general formula HRNH, in which R is an alkyl radical. Thus, according to the process conforming to the addition, the aldehyde function of lactose is blocked by the group H RNH This blockage prevents crystallization lactose and the formation of two distinct phases. The reaction of lactose with urea is preferably carried out by mixing lactose or whey, generally diluted in water, for example at a ratio of 50% by weight of solids, with urea or melamine at a ratio of at least one mole of urea or melamine per mole of lactose. The mixture is kept under stirring for half an hour to two hours at a temperature of no more than 850°C. As the condensation of urea onto the OH groups of lactose is also obtained under these same conditions, the final product can be considered a thermosetting resin and, indeed, can be used as such in the manufacture of counter- plated or other glued products. In this case, it is helpful to rapidly cool the final product (for example, with ice water) to give it a smooth surface. However, such adhesives only thermoset under pressure (i.e., using a press) and not at ambient pressure. Indeed, at ambient pressure, it caramelization occurs, forming a soluble magma. The hemiacetalization of lactose can also be carried out at room temperature by mixing lactose or whey with a molar excess of an alcohol such as methanol or ethanol. A white deposit forms slowly and may spread throughout the entire mass of the product. According to another version of the process according to this addition, instead of using methyl or ethyl hemiacetal or another, a chlorinated hemiacetal of the form CH 3 - HI ORC Ci o CH3 is the radical of methanol. For this purpose, the procedure is the same as in the case of the hemiacetalization of lactose by methanol, but hydrochloric acid is added in a proportion of at least one mole of acid per mole of lactose. This chlorinated hemiacetal can also be used to create thermosetting resins with urea, melamine or phenol or other compound with an active hydrogen function, by mixing it with such a compound under the same conditions as if it were not chlorinated. The pH can then be readjusted to a more basic value by adding, for example, sodium hydroxide flakes to the solution.
Claims
DEMANDS 1. A process for manufacturing a concentrated and stable solution containing a lactose derivative according to claim 1 of the main patent, characterized in that an amine is added to the solution.
2. A method according to claim 1, characterized in that the amine used is urea.
3. A method according to claim 1, characterized in that the amine used is melamine.
4. A process according to any one of claims 1 to 3, characterized in that the amine is added to the solution at a rate of at least one mole of amine per mole of lactose.
5. A method conforming to one of the claims 1 to 4, characterized in that after the addition of the amine, the The mixture is kept under stirring for half a one to two hours and at a temperature at most equal to 850 C.
6. A process according to claim 1 of the main patent, characterized in that alcohol and hydrochloric acid are added to the solution.
7. A process according to claim 6, in that at least one mole of hydrochloric acid is added per mole of lactose.
8. A process for manufacturing a thermosetting resin in which the solution obtained according to the process conforming to one of the claims 1 to 7, on a chemical compound having a hydrogen function.
9. A process according to claim 8, characterized in that the compound having a hydrogen function is selected from phenol, urea, and the melamine.