DE2460223A1 - PLASTICIZED AMINOPLASTIC RESIN COMPOSITES - Google Patents

Description

The invention "relates to plasticized aminoplast resin compositions.

It is "known that in the manufacture of aminoplast mold- '. materials in the formulation a plasticizer must be introduced in order to achieve satisfactory processing properties. The plasticizer must be completely compatible with the aminoplast resin in order to have a good gloss and good shine To give surface quality as well as the flow behavior to improve the quality of the material during molding. Relatively few connections meet all the requirements for a good plasticizer, and most of them are uneconomical in technical application.

According to the invention, a thermosetting plastic composition comprises: '. -. a) a plasticizer that includes an alkyd that is practical is free of -COOH groups and:

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(i) a mono-, di- or tricarboxylic acid component as

Acid component,
(ii) the component of an alcohol has 1 "to 4 OH-G groups

as an alcoholic component, iind
(iii-) a total of no more than 20 acid and alcohol units

th has; and "b) an uncured aminoplast resin.

Preferably the alkyd contains no more than a total of 15,
in particular not more than 10 and even more preferably not more than 7 acid and alcohol units.

It can be seen that the term "acid and alcohol units" the groups "denotes which of the acid component and the alcohol component are derived, as they are present in the alkyd in connected form «

The acid component is preferably a benzene dicarboxylic acid and / or an aliphatic dicarboxylic acid having 4 to 9 carbons. material atoms, and the alcoholic component is preferred a diol or triol of 2 to 10 carbon atoms.

The alkyd can have a molecular weight of 250 to 800 or even higher; Alkyds with molecular weights in the range of 250 to 400 are currently preferred. The molar ratio of the
Acid component to alcoholic component can fluctuate accordingly, for example from 1: 2 to 3: 4 *

Alkyds that can be used as plasticizers for both
Urea -]? Ormaldehyde resins (UP) and melamine-formaldehyde resins (ME ¹ ) are suitable, include those based on adipic acid and phthalic acids, such as polyethylene terephthalate, polyglyceryl phthalate and polyglyceryl adipate; other alkyds, as defined above ·, but are not suitable for MF resins for

UP resins.

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In some cases the plasticizer is preferably modified "for example by using a mixture of alkyds or an alkyd with one or more acid components with 2 or more alcoholic components, or an alkyd with one or more alcoholic components with two or more acid components,

For example, polyethylene terephthalate (EET) was made in two directions Modify:

(i) replacement of part of the ethylene glycol with propylene glycol, Glycerine or butane (i, 4-) diol leads to alkyds which are excellent Plasticizers for certain T-IF and UP resins are when the molar ratio of glycol to acid is 2: 1 "and the ethylene glycol is 75 mol $ of the glycol component (i.e. the alcoholic component) represents. However, if propylene glycol or glycerin is 50 mole $ of the glycol component represents, the alkyds are much less "preferred as plasticizers,

(ii) Replacement of "up to 50 moles of the terephthalate component (Acid component) by phthalate (from. Any of the Phthalic acids) is possible and leads to good plasticizers for both UF and MF resins "the substitute for equal proportions of adipate (from adipic acid) lead to good plasticizers for MF Harζe, but if If glycerine is not also added (which results in a four-component system) these alkyds are unsuitable for Plasticization of UP resins, in a four-component system it is preferred that there be at least one mole of glycerol for every mole of adipic acid when the alkyd is sufficient should be compatible with a UP resin.

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Similarly, diglyceryl adipate (I) GA) with ethylene and propylene glycol and butane (1,4) diol and with Neopentyl glycol "at a glycol: acid molar ratio modified from 2: 1. If glycerin is 75 moles of the glycol component represents, good molding compositions can be obtained, with the exception of the fact that the use of Ne opentylglykol provides a modified alkyd that is incompatible with UF resins. When ethylene glycol is 50 mol $ the GIyko! Component can have satisfactory dimensions can be obtained. 33 mol $ of adipic acid were replaced by eththalic anhydride and 20 mol? o replaced by azelaic acid in this type of alkyd, with good results,

However, diglycery lactelate, which is compatible with MF resins, is incompatible with UF resins "

In general, optimal results are obtained with any type of alkyd when the alkyd has a very low acid number, d. H. less than 1.0 but it is possible to obtain satisfactory compositions in which the acid number is slightly higher. For example, diglyceryl adipate alkyds having acid numbers of about 7.0 have been used in accordance with the invention. Such alkyds, i. H. those with an acid number of less than 10 'are in the present case as "practically free of.-C00H groups" according to considered the definition above. The acid numbers can be reduced by reacting the alkyd with a compound which is reactive with carboxyl groups, such as ethylene carbonate or an epoxide, such as the substance under the trade name "Cardura E" is available.

In general, the alkyds used are also selected in view of cost. The inclusion of small quantities other compounds with plasticizing properties is not excluded.

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The alkyd is generally present in an amount of about 5 ° or less based on the weight of the alkyd plus resin, but may also be present in higher amounts if desired, "for example" up to 50% by weight . The total amount of ·. Plasticizer, ie alkyd plus other plasticizer used in the bulk, generally does not exceed 10% by weight.

Commercially available polyester alkyds are generally not suitable as a plasticizer for amino resins, what on is due to their hydrophobic character.

The following examples illustrate the invention on the basis of preferred embodiments.

Examples A and B.

Terephthalate alkyds were made by reacting dimethyl terephthalate with ethylene glycol or ethylene glycol and glycerin in the presence of 0.1% by weight of an acid catalyst in the ones given below molar ratios until the amount of methanol formed indicated that the esterification reactions ended. The product was a white pest substance in each pail. .

(a) dimethyl terephthalate. . 2 moles. Ethylene glycol 5 moles

(b) Dimethyl terephthalate 2 moles of ethylene glycol 3 moles Glycerine 1 mole

Examples 0 and D

Adipate alkyds were made by reacting adipic acid with glycerine or made with glycerine and ethylene glycol in the molar ratios given below until the acid number of the product

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1 Mole 2 Mole 2 Mole 3 Mole 1 Mole

was less than 5 . That. Product was a yellow liquid in each case.

(c) 'adipic acid glycerin

(d) adipic acid glycerine ethylene glycol 1

Example E '.

An o-phthalate alkyd was made by reacting 2 moles of glycerine with 1 mole of phthalic anhydride until the acid number of the product less than 5 was made. The product was a viscous one

Liquid.

Examples 1 to 5

Five alkyd plasticized urea-formaldehyde resins were prepared by mixing 10 parts by weight of each of the above alkyds with 210 parts urea-formaldehyde resin having a urea to formaldehyde molar ratio of 1: 1.33 and a solids content of 62.5 ° . The obtained resin was mixed with 70 parts of paper pulp, 3 parts of catalyst, 4 parts of a buffer and 1 part of a mold release agent in each case. This mixture was dried at 80 ⁰ C in an air oven, until the free water content was about $ 1, and the obtained chips were crushed and ground to a fine powder. The powder was extruded and the extrudate crushed to form a granular molding compound.

Comparative example

A granular molding compound was produced as described above, however, the alkyd has been omitted.

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Examples 6 to 10

Five alkyd-plasticized melamine-formaldehyde resins were made by Mixing 10 parts by weight of each of the oMgen alkyds with 230 parts of a melamine-formaldehyde resin with a molar melamine eu poria aldehyde ratio of 1: 2 and a pesticide content of 57 1 ° . The resulting resin was mixed in each pail with 62 parts of paper pulp and 1 part of a mold release agent, and the resulting mixture was treated as described above for the urea ormaldehyde materials.

The results of the tests carried out on these porous materials are summarized in the following table:

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Example,

"· 5. Yergl · 6 7 8 9 10

A2fcyä A B C IiE -AB C D E

content (wt, - #) - 1.1 1.1 1.2 1.2 1.1 1.6 ί, 2 1.2 1.1 1.1 0.9

flow of the λ-μ

Materials (mmr '' 9.14 8.58 7.37 7.62 9.65 8th, 89 6.6 8.13 8.38 7.87 9.4

ο ^ form shrinker r '0.62 0.60 0.75 0.72 0.60 0.75. 0.70 0.72 0.60 0.68 0.90

£ very corpse ^ ^; 0.45 0.55 0.75 0.55 0.65 0.85 0.50 0.30 0.75 0.50 0.68 f

ο surface- '- ⁰ ^ ι

c © look good good good good "good very good good good ■ good good

° bad

Remarks;

Yergl. - Comparison game

(1) - Thickness of a disc, which was pressed from 80 g of material with a force of 28 t became

(2) - according to British Standard 2782 - Method 106B

(3) - according to British Standard 2782 - Method 106E

CD Ni K)

It is known that molding materials have good flow properties can be generated by eliminating high levels of free water * However, such materials have disadvantages like poor dimensional stability. When the free water content is reduced to one degree, i.e. good stability shows that the obtained material tends to have other IT parts such as decreased formability? then a plasticizer or other additive must be used in order to avoid or ameliorate these disadvantages.

However, the above table shows that aminoplast molding materials with a low free water content, however, good flow properties are obtained by using an alkyd as a plasticizer can be.

The plasticizers shown above as examples are considerably cheaper than plasticizers as they are currently used, and have considerable versatility in application.

- patent claims -

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Claims (10)

Claims 1 · Thermosetting plastic molding compounds containing an uncured aminoplast resin and a plasticizer, characterized in that the plasticizer comprises an alkyd which has an acid number of less than 10, and
(I) as the acid component one of mono-, di-, or Tricarboxylic acids,
(ii) an alcoholic component consisting of alcohol with 1 "to 4 OH groups, and
(iii) no more than 20 acid and alcohol units in total having. 2. Plastic compound according to claim 1, characterized in that the alkyd has a total of less than 7 acid and alcohol units having. 3. Plastic compound according to claim 1 or 2, characterized in that that the acid component is a Benaoldicarboxylic acid and / or an aliphatic dicarboxylic acid with 4 "to 9 carbon atoms is* 4 «plastic mass according to one of the preceding claims, characterized in that the alcoholic component is a diol or triol having 2 to 10 carbon atoms. 5. Plastic compound according to one of the preceding claims, characterized in that the alkyd has a molecular weight in the range of 250 Ms 800. 509828/0809 c I t I 6. Plastic compound according to one of the preceding claims, characterized in that the molar ratio of
Acid component to alcoholic component in the area
from 1: 2 to 3 ι 4 is. 7. "Plastic compound according to one of the preceding claims, characterized in that the alkyd has an acid number less than 1.0. ■ · ■ 8. Plastic compound according to one of the preceding claims, characterized in that the alkyd is an alkyd with a relatively high acid number, which is used to reduce the acid number is modified by reacting its carboxylic acid groups with ethylene carbonate or an epoxide. 9 plastic compound according to one of the preceding claims characterized in that the plasticizer in an amount of not more than 10% by weight, based on "plasticizers and Aminoplast resin. 10. Plastic compound according to one of the preceding claims, characterized in that the alkyd in an amount of not more than 5% by weight, based on plasticizer and aminoplast resin, is present. ■ · ' 509828/0809