DE1795040C - Process for the production of matted shaped bodies from cellulose esters - Google Patents

Description

a) They contain at least 1 "Io free hydroxyl groups, ₅ groups and are either homogeneous esters,

d. H. Esters with only a single acyl substituent type, or mixed esters, d. H. Esters with more than one acyl ester type, and / or

b) they are cellulose mixed esters, their ester substituents differ in their carbon content by more than 1 carbon atom, each produced in a known manner are,

groups, cellulose tripropionate with at most 0.5% free hydroxyl groups and cellulose tributyrate with at most 0.5 · / · free hydroxyl groups

6. Process according to Claims 1 and 2, characterized in that one of molded bodies starts out, the stabilizer potassium hydrogen oxalate, strontium naphthenate or p-tert-butylphenol contain.

7. The method according to claims 1 and 2, characterized in that one of molded bodies goes out, the up to 25% of the plasticizer Triethylene glycol di-2-ethylhexoate, triethylene glycol dW-ethyusohexoate, butyl sebacate, contain mixed octyl adipates, dibutyiacelate or di (2-ethylhexal) azelate.

Cellulose esters are used in the manufacture of the most diverse Shaped bodies are used because they are relatively cheap and easy to work with. Such However, molded bodies have the disadvantage that they often have a not inconsiderable light reflection are very smooth.

It now exists, for example in the course of a

agents, the at least partial solvents 30 safer design of automobiles, a big one for the cellulose esters there is, in the usual way, a need for suitable materials for production of molded bodies, such as dashboards, switches, buttons and steering wheels that allow only a slight or no light reflection 35 and next to it, for example in the form of steering wheels or switches that have a better grip when operated or a higher frictional resistance Offer.

There has therefore been no lack of attempts to make matting by roughening or other processes, For example, to produce moldings suitable for use in automobiles, which reduced a Have light reflection and have a better grip. Moldings with such properties

cellulose acetate propionate transactions, or w are, for example for the production cellulose propionate butyrate with each other and at least of table tops and wall panels Ge 1 ⁰ Zo free hydroxyl groups exists. objects whose natural or artificial

4. The method according to claims 1 and 2, borrowed light reflection should be as low as possible,
characterized in that one of moldings The invention is now based on the object of a pern whose geometrically regular 5 ° improved process for producing matt cellulose ester portion consists of cellulose esters, 'to indicate moldings made of cellulose esters, one in which at least Vs of the bound acyl radicals

consists of fatty acid residues with 3 to 4 carbon atoms and in which 95 "/ o of the total bound acyl residues differ from one another by at most 1 carbon atom, which contain at most 0.5 vol free hydroxyl groups and which have an intrinsic viscosity even after 30 minutes of heating at 250 ° C - measured in a mixture of 9 parts of methylene chloride and 1 part
ethanol - greater than 1.

5. Process according to Claims 1 and 2, characterized in that one of molded bodies goes out, whose geometrically more regular

and to 80 to 20 percent by weight of crystalline, geometrically regular d. H. completely petrified Cellulose esters, in vapors of solution

depends on the fact that these can condense on the shaped body and flow off during the subsequent drainage wash off the surfaces of the moldings.

2. The method according to claim 1, characterized in that the solvent used is trichlorethylene, Methyl acetate, ethyl acetate, butyl acetate, benzene, chloroform or methylene chloride used.

3. Process according to Claims 1 and 2, characterized in that one of molded bodies goes out, whose amorphous, geometrically irregular cellulose ester portion from cellulose compartment and can be carried out cheaply and results in molded articles with at most low light reflection and excellent Grip leads.

The invention is based on the knowledge that the problem can be solved by Shaped bodies made of certain cellulose ester mixtures treated with solvent vapors.

The subject of the invention is therefore a process for the production of matted molded bodies Cellulose esters, which is characterized in that molded bodies consisting of 20 to 80 percent by weight made of amorphous, light-crystalline, geometrically irregular cellulose esters, which have an intrinsic

Cellulose esterant ¹ from cellulose acetate propionate 65 viscosity - measured in a mixture of 9 parts with a maximum of 20 * / »acetyl groups ukJ at most methylene chloride and 1 part methanol - have more than 0.5% free hydroxyl groups, cellulose propionate than 1 and the following others Natbutyrate with a maximum of 0.5%> free hydroxyl features are:

a) They contain at least 1 · / · free hydroxyl mainly from acetic anhydride, acetic acid groups and are either homogeneous esters, and sulfuric acid as a catalyst. In the case of CeI-d. H. Esters with only a single acylulose acetate butyrate are of the (liquid) esterification type, or mixed esters, d. H. Ester means either from butyric anhydride, acetic acid with more than one acyl ester type, and / or 5 and sulfuric acid as a catalyst or from acetic

b) they are mixed cellulose esters, their ester acid anhydride, butyric acid and sulfuric acid as their carbon content included more catalyst. The respective composition of the zuals 1 carbon atom, the last-mentioned esterifying agent depends on have been prepared in a known manner, whether a high or low butyrated ester is produced

ίο BE The amount of ER in the esterification _V

and is 80 to 20 weight percent based on crystalline turned sulfuric acid catalyst geometrically regular, d. h, completely based on the dry weight of the cellulose, 1.5 to 10 »/ o esterified cellulose esters, in vapors of solution sulfuric acid. To use esters with good viscosity properties, the at least partial solvent for the shafts should be the esterification temperature Cellulose esters are, in the usual way, that 15 usually do not rise above 37.8 ° C. The respective These can condense on the moldings, however, depends somewhat on the esterification temperature and during the subsequent draining off the surface amount of the sulfuric acid catalyst used. wash off the shaped body. This dependence is such that the temperature

The treatment of shaped bodies made of cellulose- the reaction mixture is controlled all the more carefully

esters with solvent vapors is known per se, the more catalyst in the Veresteningsge-

and is often referred to as "steam polishing" is mixed. To end the suppuration,

Shaped bodies made from conventional cellulose esters are usually given enough water for the reaction mixture

but in the treatment with solvent vapors in the form of aqueous acetic acid, added to the remaining

fcn, d. H. when »steam polishing«, highly polished borne acetic anhydride to hydrolyze acetic acid

Surfaces. Surprisingly, it has now been shown that » The reaction mixture is either equal to

that when you start with shaped bodies made of cellulose or with the, if necessary

esters of the aqueous acid used in the process of the invention, a new

th composition solvent vapors were added, which with a considerable

ken, no highly polished, but matted borrowed amount of sulfuric acid to an in the reaction

Surfaces are preserved. 30 tion mixture insoluble salt reacts. To this

The modified by the method of the invention purpose have magnesia and magnesium compounds

ble moldings can thus, for example, fertilize weak acids such. B. magnesium carbonate,

Be steering wheels for automobiles, which proved to be particularly advantageous as the formed

Reduced light reflection and better grip. Magnesium sulfate is insoluble in the reaction mixture.

and consequently also through greater security 35 Since hydrolysis is desired, the greater part will

distinguish. of the present catalyst neutralized and the

The cellulose esters from which the hydrolysis is carried out after the hydrolysis, but with the content of

drive the invention produced, matted shape-bound sulfuric acid in the finished ester one

body consist, preferably contain acylsubsti- sulfur content of 0.02 to 0.00l «/ o should correspond,

tuents with 2 to 4 carbon atoms. 40 When carrying out the hydrolysis of the cellulose

Among amorphous, non-crystalline, geometrically esters, the reaction mixture should be in the form Irregular cellulose esters are such cellulose- an aqueous acid incorporated water with an To understand esters, which practically do not crystallize, are added at such a rate that it if they are incorporated evenly into the hydrolysis mixture according to thermoplastics conventional pressing or casting processes are processed. With the addition of the aqueous acid and walls. The lack of crystallizability such rend the hydrolysis is said to be the temperature of the reac cellulose ester is known to be mainly due to its ionic mixture at 43.3 to 82.2 C " attributed to geometric irregularity. the desired degree of hydrolysis of the cellulose ester er-these Cellulose esters are usually by min- is, which is the case when the cellulose esters at least one of the two below-mentioned 50 contains more than IVo free hydroxyl groups Characteristics characterized: the ester precipitated by the addition of aqueous acid and filtered off. The ester obtained is then added

1. They contain at least IV 'free hydroxyl completely, preferably several times, gegruppen with water and are either homogeneous esters, washing, wherein the washing water has a low ie, esters having only a single acyl ₅₅ mineral content preferably a Mineralstoffsubstituententyp or Mischester, ie Ester content of less than 20ppm should have. Before using more than one type of acyl ester, and / or preferably used here as wash water

2. They are mixed cellulose esters, their ester-substituted water or water with a permutittuent water that has been treated with more ion-exchangers in terms of its carbon content.

differentiate than 1 carbon atom (e.g. ^6o The one used to carry out the process of the Erfin cellulose acetate butyrate). Suitable cellulose butyrates can, for. B.

according to an already proposed method

The cellulose ester types described are crystal-clear. Following this procedure you can toluene in conventional pressing or casting processes, cellulose butyrates which are practically soluble by heating a table not. 65 Mixture of (a) cellulose butyrate with at least

The esters of the type described can be classified according to about 52% butyryl, 0 to 1.5% acetyl and well known Process. In the case of cellulose 0.25 · / · hydroxyl groups and at most loseacetaten consists of the (liquid) esterifying agent 0.006Vo sulfur in the form of sulfate groups and (b)

at most about 30 · /. free water, based on the ceaulose ester mixtures used Weight of the liquid chains in the hydrolysis bath, possibly up to 25 percent by weight an essentially butyric acid based on the cellulose ester mixture, Plasfafmerungsnattei solvent system to a temperature of about included. Suitable plasma cooling agents are at -23.9 up to about 148.9 ° C. Here 5 for example ΤΒ3% 1βη ^^ 1-Λ-2-3ών1-κο1.εχο3ί, the reaction mixture is heated until the octyl adipate, dibutyl acetate and di (2-ethylhexyl) hydroxyl group content of cellulose butyrate to azelate. ,

about 1 to 3.2 · /. It should be noted that tons of CeUulose ester mixtures

that the reaction mixture contains practically no sulfuric acid, as well as other inert conventional additives and does not contain free fatty acid anhydrides. u become alive. So the jCellulose ester mixtures,

The intrinsic viscosity of the amorphous, non-crystalline depending on the desired color, toughness and Linen, geometrically irregular esters, like the flexibility of the molded bodies made from them, should also be included In the case of the geometrically regular cellulose, for example up to 1 percent by weight of pressed or cast ester According to the measuring method described later, aids such as paraffins, furthermore, color measurements can be greater than 1. 15-substances, fillers and / or extenders incorporated

Under geometrically regular cellulose esters are.

are practically completely esterified cellulose esters in the treatment of moldings made from conventional

to understand. They lie in the Jem process cellulose esters with solvent vapors, matted molded bodies which can be produced according to the invention, as already mentioned, highly polished surfaces in crystalline form. At least a third of the *> receive. Shaped body from the acyl radicals bound in the context of the Verin these esters consists of cellulose used according to the invention • Fatty acid residues with 3 to 4 carbon atoms. Furthermore eslcra received in contrast with the treatment with these esters contain a maximum of 0.5 · /. Hydroxyl solvent vapors create a matt surface. j

groups. The treatment of the moldings with a solution groove j

After 30 minutes of heating to 250 ° C in an as teldampf can be carried out in the usual way 9 parts of methylene chloride and 1 part of methanol. As a rule, the moldings are used here they have existing solutions, like the geometrically concentrated organic ones! "Solvent dampers j

uncrystalline ester, an intrinsic viscosity of min- z. B. out-n over a typical degreasing bath. j

at least 1. The measures required to carry out such a treatment - j

In the case of mixed cellulose esters, the apparatus used should be known. Fm ₁ - ι

Acyl residues contained therein from each other not around such a device consists of a stand uprightmore differ as 1 carbon atom. Tsar the tank, which is open or iu at its top Carrying out the method of the invention is suitable and has a container on its underside Nete, geometrically regular cellulose esters are located for the solvent. This container by sample Cellulose tripropionate, cellulose- 35 contains a certain amount of the solvent, which i

butyrate, Cellulosepropionatbutyrat and Celluloseace- something below, on or e'was above its boiling point ι

Tatpropionat is heated with a maximum of 20% acetyl. Since the entire device is in the rain! group salary. She is subject to all of these esters in which it is open to its surroundings Usually a maximum of 0.5 ° /. free hydroxyl groups at atmospheric pressure. Keep an outflow of the solution. 40 medium vapors through the side walls of the container

Suitable, geometrically regular cellulose can be prevented by a condensation device ester can, for example, according to that in the USA or other devices. A patent specification 3 047 561 described process or conventional device consists of an esterification process on the inside, in which zinc chloride or other, no binding 45 overflow edge is attached as a catalysis of the tank and gates around it, which is about halfway through, For example, no sulfur bonds - tank height is attached. In the overflow edge testifying compounds, such as methane, there is circulating cold water. Trisullonic acid can also be used. Find use, be produced. To condense the solvent vapors, the cellulose ester is not used after its production, a cold air stream which hydrolyzes to such an extent that its hydroxyl group content rises in the middle or in the lower third of the tank by more than 0.5 ^e / o all around. This is blown in in the manner described.

Cellulose ester produced with the specified The molded body to be treated is in the

Intrinsic viscosity can advantageously be stabilized in concentrated solvent vapors, preferably in stabilization processes as described in US Pat. Suitable Stabili- that the solvent vapors on the molding are for example monopotassium oxalate per condense and after sufficient condensation (KHC ₂ O ₄ ), strontium naphthenate and p-tert-butyl as a condensed solvent in the heated ι

phenol. Flow back solvent container. During the j

The cellulose ester mixtures from which the after 60 takes two to three seconds or several minutes

the process of the invention producible, mattifying treatment, what from the respective combination Shaped bodies can exist by simply composing the shaped body, the solvent Mixing the cellulose ester components described, and depending on the desired matting, takes place for example 'by mixing in a rubber roller through the condensation of the solvent on the mühle, or according to other customary processes, a superficial dissolving process for shaped bodies where a homogeneous mixture of the individual loading takes place, with a very small part of the molding j

stamllcilc arises, to be produced. washed away by the condensed solvent i

Who will be in the implementation of the procedure. Presumably this is the

7 ~ 8

amorphous portions of the cellulose ester mixtures, which identify that they are produced again

as a result of their faster dissolution rate in the described treatment with solvent vapors exposed to the solvent quickest. Are the moldings after the process

will. made of the invention, they keep their mat-

When carrying out the method of the invention, the surface area will be 5, depending on the context the temperature of the solvent vapors composition of the molding, even rougher, while exposed molded body lower, d. H. at least moldings made from other cellulose ester mixtures, 5 ° C lower than the temperature of the solution, for example from mixtures of amorphous cell medium vapors, so that these are loosely stuck on the molding, their surface matting by condensation be able. to rough was generated, in the described treatment

To carry out the method of the invention treatment with solvent vapors a smooth and in suitable solvents are those which in some cases also have a highly polished surface Hold »steam polishing« from moldings.

usual cellulose ester mixtures of amorphous, non-B e i s ο 'e 1

crystalline and geometrically irregular cellu- 15 ^p

loosely can be used. Preferably from a cellulose ester mixture, consisting of

Solvents used are trichlorethylene, 36.3 ^e / o cellulose tripropionate esters with 0.1% free

Butyl acetate, methyl acetate, ethyl acetate, benzene and hydroxyl groups, 54.6 "/" cellulose acetate propionate

chlorinated solvents, such as chloro esters with 2.2 ⁰ ZoACeIyI and 45.7% propionyl

form and methylene chloride. Particularly suitable ao groups and 2.1 ⁰ Zo free hydroxyl groups and

Trichlorethylene has been found, since this was not 9.1% dibutyl sebacate as a plasticizer,

is flammable. by means of a screw press with a cylinder

Following the treatment with a solvent temperature of 232.2 ° C and a temperature of 126.7 ° C

The moldings are preferably steamed using heated casting mold bars with a thickness of 6.35 mm,

"Hardened" to completely remove the remaining solvent, with a width of 12.7 mm and a length of

to remove. For this purpose, the molded article is pressed 127 mm.

heated to a temperature that was at least somewhat for comparison purposes from a cellulose over the normal boiling point of the solvent, but ester mixture consisting of 90.9 Vo cellulose acetate considerably below the melting point of propionate esters with 2.1% free hydroxyl groups the shaped body lies. If the boiling point of the solvent is 30 and 9.1% dibutyl sebacate as a plasticizer, solvent close to the melting point of the molding - by means of a screw press with a cylindrical temper, for example, the treatment with a solvent temperature of 232.2 ° C and one to 48.9 ° C can be used to heat steam and the subsequent hardening in a vacuum th casting mold also rods with a thickness of be carried out to the boiling point of the Lö- 6.35 mm, a width of 12.7 mm and a length to lower the solvent. 35 of 127 mm pressed. The from the cellulose tri-

The modified by the process of the invention and containing the hydrolyzed ester cell

molded bodies can be injection molded, lulose ester mixture pressed rods were 5 seconds

Casting processes or other methods for molding long thermals in a tri-zone heated to 86 ° C

Solvent vapors that are suitable for thermoplastic plastics and are present in a chloroethylene bath

th process. 40 hanged. They received a matted, blunt upper

A surface obtained by the method of the invention. The frosted rods were then

As a result, matted shaped body is generally in an oven for 20 minutes with air circulation

indicates that it is essentially made of crystalline "hardened" at a temperature of 90 ° C to obtain the

and geometrically regular cellulose ester asole - remaining solution remaining on the rods

cool and the geometrically irregular 45 substances stored therein evaporate completely 7u,

moderate and consequently amorphous cellulose estennole- When treating the cellulose triester

kulen consists. The precise structure of the rods holding moldings made their surfaces strong

depends on the ratio of the present crystalline glossy,

and non-crystalline cellulose ester molecules. The low gloss of after the process of

A matted molded article obtained by the process of the invention, the

Matted molded body is also characterized in that the solvent is preferably used

shows that the X-rays recorded with it attack the amorphous ester, can be attributed to it-

radiation diffraction fields for cellulose esters characterize that either a series of fibers of the crystalline

which are to a considerable extent made up of crystalline esters, between which the amorphous ester is formed.

stable cellulose esters exist. 55 was removed from the surface of the molded body

Matted molded body that protrudes such characteristic or by the fact that the solvent

Exhibit X-ray diffraction patterns, preferably attack the amorphous ester surface,

as a result of the method of the invention whereby micro-hairline cracks arise on this.

209 686'3K

Claims (1)

Patent claims: 1. Process for the production of matted moldings from cellulose esters, characterized in that molded bodies are made 20 to 80 percent by weight of amorphous, light-crystalline, geometrically irregular Cellulose esters that have an intrinsic viscosity - measured in a mixture of 9 parts methylene chloride and 1 part methanol - greater than 1 and by the following further features are characterized: