GB2023623A - Modified melamine- formaldehyde condensation products - Google Patents
Modified melamine- formaldehyde condensation products Download PDFInfo
- Publication number
- GB2023623A GB2023623A GB7921816A GB7921816A GB2023623A GB 2023623 A GB2023623 A GB 2023623A GB 7921816 A GB7921816 A GB 7921816A GB 7921816 A GB7921816 A GB 7921816A GB 2023623 A GB2023623 A GB 2023623A
- Authority
- GB
- United Kingdom
- Prior art keywords
- formaldehyde
- melamine
- urea
- hydroxymonoamine
- aliphatic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/47—Condensation polymers of aldehydes or ketones
- D21H17/49—Condensation polymers of aldehydes or ketones with compounds containing hydrogen bound to nitrogen
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G12/00—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
- C08G12/02—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes
- C08G12/26—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic compounds
- C08G12/34—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic compounds and acyclic or carbocyclic compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G12/00—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen
- C08G12/02—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes
- C08G12/26—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic compounds
- C08G12/34—Condensation polymers of aldehydes or ketones with only compounds containing hydrogen attached to nitrogen of aldehydes with heterocyclic compounds and acyclic or carbocyclic compounds
- C08G12/36—Ureas; Thioureas
- C08G12/38—Ureas; Thioureas and melamines
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Phenolic Resins Or Amino Resins (AREA)
Abstract
Improved resins are obtained by substituting urea for part of the melamine in known cationic water- soluble resins obtained by interaction of melamine, an aliphatic hydroxy- monamine such as triethanolamine, and formaldehyde. The new resins, which have molar ratios melamine:urea:hydroxyamine:formaldehyde in the range 1:0.25-8:0.1-25:4-30, have a faster curing rate and better stability in the liquid state for a given content of formaldehyde.
Description
SPECIFICATION '
Modified megamine-formaldehyde condensation products
This invention relates to the preparation of melamine-formaldehyde condensation products, and particularly such products as are modified with aliphatic hydroxymonoamines.
Examples of such modified melamine-for:maldehyde condensation products are disclosed in the specifications of our UK Patents 1 305 187 and 1 317 774.
There are described in Specification l 305 187 certain cationic water-soluble melarnineformaldehyde resins modified with an aliphatic hydroxymonoamine which are specially useful for imparting wet-strength to paper. These resins are obtainable by a two-stage process carried out in aqueous medium, both stages being operated with control of pH. In the process, the molar ratio melamine:formaldehyde employed is in the range 1:2-1 :6 and'the solidscontent of the sy5tem is at least 60% by weight.By this'we mean that weight of reactants/(weight of reactants + aqueous medium) is at least 60%:
In Specification 1 317 774 there are described certain cationic water-soluble melamine formaldehyde resins modified with an aliphatic hydroxymonoamine which are different from those of
Specification 1 3051 87-in being 'high formaldehyde' resins they have a molar ratio formaldehyde:melamine greater than 6:1). These resins are useful in anchoring rncistureproof coat.ings to regenerated cellulose film.
'The aliphatichydroxymonoamine employed in forming the resins described above are of the general formula Ii 1R2N-R-0H where
R is lower alkylene (preferably (CH2)2 or (CH2)3) : Ra is hydrogen, a lower alkyl group (preferably CH3 or C2H5) or a hydroxy lower alkyl group (preferably (CH2)20H or (CH2)30H), and
R2 is a lower alkyl group (preferably CH3 or CzH5) or a hydroxy lower alkyl group (preferably' (CH2)zOH or (CH2)30H).
Examples of such aliphatic hydroxymonoamines are: triethanolamine; tri-n-prnpanolamine, diethylaminoethanol and dimethylaminoethanol.
We have now found that, by substituting urea for part of the melamine employed in the production of hydroxymonoamine-modified melamine-formaldehyde resins, there can be obtained new resins of faster curing rate and improved stability in the liquid state for a given content of formaldehyde.
Additionally, when employed so as to modify the kind of resin described in UK Specification 1 305 187, the substitution results in resins which develop wet strength in paper relatively quickly at ordinary temperature and humidity, a property which is specially useful when manufacturing tissue and towelling on high speed machines.
The new resins are condensates of melamine, urea, an aliphatic hydroxymonoamine and formaldehyde in the following molar proportions:
Hydroxy
Melamine Urea monoamine Formaldehyde 1 0.25-8 0.1-2.5 4-30 and with a molar ratio formaldehyde: each amino-hydrogen atom in the range 0.5-2.25:1. (Melamine, C3N3(NH2)3 has 6 amino-hydrogen atoms; and urea, CO(NH2)2, has 4 amino-hydrogen atoms.)
In preparing resins suitable for use in paper treatment, the molar ratio melamine:formaldehyde employed is in the range 4-24, with a molar ratio formaldehyde: each amino-hydrogen atom in the range 0.5-1.25:1.Preferred proportions for such resins are:
Hydroxy
Melamine Urea monoamine Formaldehyde 1 1.5-3.5 0.5-2 10--15
In preparing resins of molar ratio formaldehyde: each amino-hydrogen atom in the' range 1.25-2.25:1, preferred proportions of the constituent substances are:
Hydroxy
Melamine Urea monoamine Formaldehyde
1 1.5-3.5 0.5-2 10-30, especially 16-28 Those resins having a molar ratio formaldehyde: each amino-hydrogen atom in the range 0.5-1.25:1 can be made starting from reaction products of an aliphatic hydroxymonoamine with formaldehyde, which are prepared as described in Specification 1 305 187: that is to say by reacting formaldehyde and hydroxymonoamine in aqueous medium, at a solids content of at least 60% by weight and at pH at least 8.5 (preferably 8.5-11), at a temperature in the range 800C reflux temperature. Such a product is then reacted with melamine and urea, at least the final stage of the reaction being carried out at reduced pH in the range 6.5-8.5, and preferably 7-7.5. The pH can be reduced by addition of a suitable acid, for example sulphuric, hydrochloric, orthophosphoric, formic or toluene p-sulphonic.The reaction is carried out at a temperature in the range 600C reflux temperature, and preferably at 85--950C, preferably until the viscosity of the system, measured at 30% solids, is 50-400 centipoise (=0.05-0.4 Pascal seconds) at 250C and preferably 100--200 centipoise (= 0.1--0.2 Pa s). The reaction product can then be diluted with enough water to make it readily pourable at ambient temperature, and then cooled to that temperature. The pH can if necessary be adjusted by addition of acid or hydroxymonoamine to a value in the range 6.5-7.5, and the product can be set aside for storage.
In the procedure just described, it is convenient to start with the hydroxymonoamine alone, using at that stage enough formaldehyde not only to react with the hydroxymonoamine but also to provide fo the subsequent addition reactions with melamine and urea.
In alternative procedures, the melamine and urea can be included, together or separateiy, in the first stage with formaldehyde and amine, or can be used initially to produce a reaction product with formaldehyde before the hydroxymonoamine is introduced.
In making those resins having a molar ratio formaldehyde: each amino-hydrogen atom in the range 1.25-2.25:1, the procedure can follow generally that described for the resins of lower formaldehyde content, but there is no need to provide for a solids content of at least 60% by weight; and this is so whether the "extra" formaldehyde is added at the first stage or (as in Example 6 later) at the last.
The invention is further illustrated by the following Examples, which relate to the preparation of storage-stable cationic resins miscible with water in all proportions at 2'50C. Examples 1-5 relate to resins of free formaldehyde content not greater than 6% by weight at 30% solids concentration, and
Example 6 to a high formaldehyde content resin, with free formaldehyde greater than 10% by weight at 50% solids concentration.
EXAMPLE 1
328.69 (9.96 moles) of 91% formaldehyde, 204.6g (2.45 moles) of 36% formalin and 3449 (2.97 moles) of 90% triethanolamine were charged to a reactor flask and the mixture (pH=1 0.5) was heated to 850C. This temperature was maintained for 2 hours, and the mixture was then cooled to 500C.
130.79 (1.03 moles) of melamine, 130.7g (2.17 moles) of urea and 3129 of water.were then added and the temperature was raised to 600 C. At this point heating was stopped and the exothermic reaction in progress was allowed to subside. The mixture was then adjusted to pH 7.1 (glass electrode at 250C) by the addition of 70ml of 90% formic acid and heating was restarted to maintain a temperature of 85-900C until the viscosity had, as a result of the condensation reaction, risen to 8Pa s (at 250C).
11009 of water were then added (solids content was then 28.5%) and the resin was cooled immediately to 25 C. Its viscosity was 58.4 centipoise (0.06Pa s) at 250C.
EXAMPLES 2,3 AND 4
The procedure of Example 1 was followed generally, but with the following differences in detail:
Material added Example 2 Example 3 Example 4 91% formaldehyde No difference No difference 219.lug (6.64 moles)
36% formaldehyde No difference No difference 136.49 (1.63 moles)
90% triethanolamine 258g (1.56 moles) 86g (0.52 moles) No difference
Water added with
melamine 8 urea 2809 2139 3009 90% formic acid 52.5ml 18ml 18ml
Final water addition 8889 730.6g 840.59
EXAMPLE 5 31 6.8g (9.6 moles) of 919/0 formaldehyde, 1 97.2g (2.36 moles) of 36% formaldehyde and 82.99 (0.5 moles) of 90% triethanolamine were charged to a reactor flask and heated at 85--900C for 2
hours. After cooling to 500C, 63g (0.5 moles) of melamine, 216g (3.6 moles) of urea and 220.89 of
water were added and the mixture was heated to 600 C. When the exothermic reaction had subsided,
the mixture was brought to pH 7 by addition of 18ml of 90% formic acid. The mixture was heated at 85--900C and, when its viscosity (measured at 250C) had risen to 8Pa s, water (731.2g) was added.
The syrupy resin was finally cooled to room temperature.
EXAMPLE 6 1 000g (12 moles) of 36% formaldehyde and 3329 (2 moles) of 90% triethanolamine were charged to a reactor flask and heated at 85--900C for 2 hours. After cooling to 500C, 1268 (1 mole) of melamine and 126g (2.1 moles) of urea were then added, and the mixture was heated to 600C. When the exothermic reaction had subsided, 60ml of 90% formic acid were added to bring the syrup to pH 7.3. The mixture was heated at 85--900C until the viscosity (measured at 259C) had risen to 24Pa s, and 320g of water were then added.Heating at 85--900C was then continued until the viscosity (at 250C) reached 6Pa s. 528g (16 moles) of 91% formaldehyde were added, and heating at 85--900C was continued (15 mins) until only a single liquid phase was present, and then for a further 1 5 minutes.
The syrupy resin was rapidly cooled to 300C and then adjusted to pH 7 with 90% formic acid. Its solids content was 48.3% by weight.
Testing of product
The resin prepared according to Example 1 was evaluated for wet-strength performance in comparison with a resin prepared identically except for the replacement of the urea by an equal weight of melamine. Hand sheets were prepared on a standard form of apparatus (British Pulp and Board
Makers Association) using bleached sulphite pulp beaten to a freeness of 320 Schopper-Reigler. In each case the equivalent of 2 parts by weight of solid resin per 100 parts of bone-dry pulp was used, the pulp suspension and backwater system being adjusted to pH 5.5 with dilute hydrochloric acid. Of the hand sheets so produced, some were cured at 850C and some were allowed to age naturally at 650F and 50% RH (relative humidity). Wet-strength values, expressed as breaking length (metres) of 15mm wide strips, were:
Natural aging at 65"F Cure time at 85 G and 50%RH Direct from machine 1 week 2 weeks 5 mlns 10 mins Example 1 resin 540 989 1217 993 1238 'All melamine' equivalent of 276 725 907 661 1224 Example 1 resin These results show faster development of wet-strength with the use of the melamine-ureahydroxyamine-formaldehyde condensate than with the use of the melamine-hydroxyamineformaldehyde condensate.
Claims (14)
1. A cationic water-soluble melamine-urea-aliphatic hydroxymonoamine-formaldehyde resin having molar ratios melamine:urea:hydroxymonoamine:formaldehyde in the ranges 1:0.25-8:0.1-2.5:4-30 and a molar ratio formaldehyde: each amino-hydrogen atom in the range 0.5-2.25:1.
2. A cationic water soluble resin according to Claim 1, in which the molar ratios melamine:urea:aliphatic hydroxymonoamine:formaldehyde are 1:0.25-8:0.1-2.5:4-24 and the molar ratio formaldehyde: each amino-hydrogen atom is 0.5-1.25:1.
3. A cationic water-soluble resin according to Claim 2, in which the molar ratios melamine:urea:aliphatic hydroxymonoamine:formaldehyde are 1:1.5-3.5:0.5-2:10,1 5.
4. A cationic water-soluble resin according to Claim 1, in which the molar ratios melamine:urea:aliphatic hydroxymonoamine:formaldehyde are 1:1.5-3.5:0.5-2:10-30 and the molar ratio formaldehyde: each amino-hydrogen atom is in the range 1.25-2.25:1.
5. A cationic water-soluble resin according to Claim 4, in which the molar ratio melamine:formaldehyde is in the range 1:1628.
6. A cationic water-soluble resin according to any one of Claims 1 to 5, derived from an aliphatic hydroxymonoamine which is a tertiary amine.
7. A cationic water-soluble resin according to Claim 6, in which said amine is a tri-(lower alkanol) amine.
8. A cationic water-soluble resin according to Claim 7, in which the tri-(lower alkanol) amine is triethanolamine.
9. A method of making a resin as set forth in Claim 1, in which the product obtained by reacting formaldehyde and an aliphatic hydroxymonoamine at elevated temperature in an aqueous medium of pH at least 8.5 and solids content at least 60% is reacted with melamine and urea at elevated temperature, at least the final stage of the latter reaction being carried out at reduced pH in the range 6.5-8.5.
10. A method according to Claim 9, in which said reduced pH is in the range 7-7.5.
11. A method according to Claim 9 or 10, in which the reaction with melamine and urea at pH in the range 6.5-8.5 is carried out until the viscosity of the system, measured at 30% solids content and 250 C, is in the range 0.05-0.4 Pascal seconds.
12. A method according to Claim 11, in which said viscosity is in the range 0.1-0.2 Pascal seconds.
13. A method of making a resin as set forth in Claim 4, in which the product obtained by reacting formaldehyde and an aliphatic hydroxymonoamine at elevated temperature in an aqueous medium of pH at least 8;5 is reacted with melamine and urea at elevated temperature, at least the final stage of the latter reaction being carried out at reduced pH in the rarge 6.5-- 5.5: and "'.e melamine-urea- hydroxyamine-forma;dehyde product so formed is reacted with further formaleashyde te obtain a product of molar ratio formaldehyde: each amino-hydrogen atom in the range 1.25-2.25:1.
14. A cationic water-soluble melamine-urea-aliphatic hydroxymonoamine-formaldehyde resin substantially as described with reference to Examples 1 to 5.
1 5. A cationic water-soluble melamine-urea-aliphatic hydroxymonoamine-fcrmaldehyde resin substantially as described with reference to Example 6.
1 6. A cationic water-soluble melamine-urea-aliphatic hydrnxymonoamine4ormaldehyde resin whenever obtained by the method of any one of Claims 9-13.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7921816A GB2023623B (en) | 1978-06-24 | 1979-06-22 | Melamine-formaldehyde condensation products |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7827825 | 1978-06-24 | ||
| GB7921816A GB2023623B (en) | 1978-06-24 | 1979-06-22 | Melamine-formaldehyde condensation products |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2023623A true GB2023623A (en) | 1980-01-03 |
| GB2023623B GB2023623B (en) | 1983-01-12 |
Family
ID=26268050
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7921816A Expired GB2023623B (en) | 1978-06-24 | 1979-06-22 | Melamine-formaldehyde condensation products |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2023623B (en) |
-
1979
- 1979-06-22 GB GB7921816A patent/GB2023623B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2023623B (en) | 1983-01-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |