JPH0231088B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to graft copolymers for thermoplastic molding obtained by polymerizing vinyl monomers, particularly unsaturated esters, in the presence of cellulose esters and ethylene/vinyl ester copolymers, and graft copolymers thereof. It concerns a mixture with cellulose ester. Cellulose acetate molding compositions cannot be subjected to thermoplastic processing without the addition of plasticizers, since this ester begins to decompose before softening. Because the softening and decomposition temperatures of cellulose acetopropionate and acetobutyrate are very close to each other, these molding compositions must be mixed with plasticizers before thermoplastic processing. This results in the required reduction in processing temperature and processing viscosity. Plasticizers used for organic cellulose esters are mainly aliphatic esters of phthalic acid, adipic acid, azelaic acid, sebacic acid and phosphoric acid,
Examples are dimethyl phthalate, diethyl phthalate, dibutyl adipate, dioctyl adipate, dibutyl azelaate, trichloroethyl phosphate and tributyl phosphate. In many cases it is also advantageous to use mixtures of plasticizers. Although cellulose ester molding compositions modified with plasticizers are very transparent, it is desirable for certain applications to further improve their thermal dimensional stability. Furthermore, the plasticizer gradually migrates to the surface of the molded article, so that modified cellulose ester films cannot be used for packaging certain food products. DE 1303219 describes mixtures of organic cellulose esters, low molecular weight plasticizers and olefin polymers. However, in view of their relatively high content of olefin polymers, such molding compositions are no longer transparent. Furthermore, the use of customary low molecular weight esters as plasticizers in this case presents all the disadvantages known associated therewith. The use of polymeric plasticizers for cellulose mixed esters is also known. US Pat. No. 3,682,850 discloses 40-90% by weight of cellulose esters and 10% by weight, which are characterized by good mechanical strength values and high transparency.
~60% by weight, vinyl acetate content 75-99% by weight
A thermoplastic mixture of ethylene/vinyl acetate copolymer is described. Furthermore, transparent thermoplastic molding compositions consisting of organic cellulose esters and ethylene/vinyl ester copolymers are also known from DE 24 26 178. The ethylene/vinyl ester copolymer used is from 30 to 98% by weight, preferably from 60 to 98% by weight.
Contains 98% by weight added vinyl esters. Blends of cellulose mixed esters and ethylene/vinyl ester copolymers containing less than 75% by weight of added vinyl ester in the ethylene copolymer component are generally transparent, but
They have been shown to have an increasing tendency to crack under bending or tensile stress as the content (by weight) of ethylene/vinyl ester copolymer in the mixture increases. This reduction in transparency is undesirable for certain applications. Inadequate compatibility of polymers makes it difficult to produce soft, flexible molding compositions that are required to exhibit high clarity without cracking. By grafting a vinyl monomer, preferably a vinyl ester and an acrylic ester or a mixture thereof, onto a mixture of an organic cellulose ester and an ethylene/vinyl ester polymer as a grafting base, or obtained in this way. The above disadvantages are avoided by mixing the grafted copolymer with another cellulose ester, and the ethylene/vinyl ester copolymer containing organic cellulose ester and up to 75% by weight of added vinyl ester. It has now been found that highly transparent, soft and flexible moldable graft copolymers based on . As a result of grafting, the graft-based polymers are completely or partially crosslinked with each other. Accordingly, the present invention essentially comprises: (1) 1 to 99% (preferably 15 to 85%); (a) 1 to 99% (preferably 20 to 95%);
), 5 to 75% by weight (preferably 25 to 55% by weight)
(b) 99 to 1% (preferably 80 to 5% by weight) of an ethylene/vinyl ester copolymer containing added vinyl ester;
), one or more aliphatic C ₁ ~
a graft base consisting of a cellulose ester of a C ₅ carboxylic acid, and (2) 99 to 1% by weight (preferably 85 to 15% by weight) of polymerized units;
one or more vinyl esters and/or alkyl esters of acrylic acid and/or methacrylic acid; and (3) from 0 to 20% by weight of one or more
C ₂ - to C ₄ -α-olefin, at least a portion of the ethylene/vinyl ester copolymer and the cellulose ester are crosslinked to each other via polymerized units of graft monomers, and the component ( The sum of 1) to (3) and the sum of (a) and (b) each amount to 100% by weight for thermoplastic molding graft copolymers. The present invention also provides essentially () from 1 to 99% by weight, preferably from 50 to 99% by weight.
one or more aliphatic C ₁ to _{C 5} of
cellulose esters of carboxylic acids, and () 99 to 1% by weight (preferably 50 to 1% by weight)
), (1) 1 to 99% by weight (preferably 15 to 85% by weight)
(a) 1 to 99% by weight (preferably 20 to 95% by weight)
(b) an ethylene/vinyl ester polymer containing from 5 to 75% by weight (preferably from 25 to 55%) of added vinyl ester; is 80-5% by weight
), one or more aliphatic C ₁
a graft base consisting of cellulose esters of ~ _C5 carboxylic acids, as well as (2) 99 to 1% by weight (preferably 85 to 15% by weight) of polymerized units;
), one or more vinyl esters, and/or alkyl esters of acrylic acid and/or methacrylic acid, and (3) 0 to 20% by weight of one or more C ₂ to C ₄ α- at least a portion of the ethylene/vinyl ester copolymer and the cellulose ester in component () are crosslinked to each other via polymerized units of the graft monomer, and component ( ) and (), the sum of (1) to (3), and (a) and (b)
also relate to thermoplastic molding graft copolymers, the sum of which amounts to 100% by weight in each case. Cellulose esters suitable for preparing the molding compositions according to the invention are cellulose esters of aliphatic carboxylic acids having 1 to 5 carbon atoms, preferably cellulose acetate, cellulose acetopropionate and cellulose acetobutyrate. Processes for the production of organic cellulose esters have been known for a long time and have been described, for example, by Ullmanns Encyklopadie der technischen.
Chemie) (Ferlag Urban und Schwarzenberg, Milunchen-Berlin,
(1963), Vol. 5, pp. 182-201. Suitable cellulose acetobutyrate is 40-50
Contains 15-26% by weight of butyric acid groups and 15-26% by weight of acetic acid groups. Cellulose acetobutyrate with the following composition is particularly suitable for the molding graft copolymer according to the invention: 42-46% by weight of butyric acid groups, and 18-46% by weight of butyric acid groups.
22% by weight acetate groups. Suitable cellulose acetopropionates generally contain 50-66% by weight propionic acid groups and 1-12% by weight acetate groups, but particularly preferred cellulose acetopropionates have the following composition: 54 ~66% by weight propionic acid groups and 4-9% by weight acetate groups. Among cellulose acetates, it is preferred to use secondary cellulose acetate. The relative viscosity (η relative) of 2% by weight in acetone of the aliphatic cellulose ester used, measured at 20° C., is between 2.5 and 6.0, preferably between 3.5 and 5.0. The cellulose esters used as graft bases for the preparation of graft copolymers generally correspond in their composition to the cellulose esters used for the preparation of mixtures, but in the graft copolymers for the preparation of mixtures. It is of course also possible to use cellulose esters other than those present in . Ethylene/vinyl ester copolymer is bulk,
It is produced by a known method of high-pressure or medium-pressure synthesis of a solution or emulsion liquid. Suitable vinyl esters are saturated, optionally halogenated, in particular chlorine-substituted, aliphatic monocarboxylic acids having 1 to 18 carbon atoms or aromatic monocarboxylic acids having 7 to 11 carbon atoms. Organic vinyl esters of acids such as vinyl formate, vinyl acetate, vinyl propionate, vinyl chloropropionate, vinyl butyrate, vinyl isoconate, vinyl caproate, vinyl laurate, vinyl myristate, vinyl stearate and vinyl benzoate, Vinyl acetate is preferred. The ethylene/vinyl ester copolymer produced by high-pressure synthesis has a molecular weight of 0.1 to 100, preferably 1.0
It has a catalytic index value (measured according to DIN 53735 at 190° C. under a load of 2.16 Kp) of ˜10, more particularly 3.5-6. in tetralin
Intrinsic viscosity measured at 120℃ is generally 0.6~
It is 1.5 [dl/g]. The molecular weight measured by light scattering method is preferably 50,000 to 1,000,000. Relational expression
Mw/Mn−1 [G. Schulz, A.Phys.
Chem. (B) 43 (1939), pages 25-34], the degree of heterogeneity U is 5-30. These copolymers are soluble in hydrocarbons or alcohols. 5, produced for example by solution or emulsion polymerization.
The ethylene/vinyl ester copolymer containing ~75% by weight of vinyl ester, preferably from 25 to 55% by weight, has a melting index (190°C/2.16Kp) that may be greater than 100. However, the melting index range is preferably less than or equal to 15, more particularly from 0.5 to 5. The molecular weight measured by light scattering method is preferably 4,000 to 1,000,000. The degree of non-uniformity U is 1-15. The copolymer is soluble in hydrocarbons and alcohols, and preferably has a
It has an intrinsic viscosity (η) of 2.5 [dl/g]. The monomers used for the preparation of the graft copolymers are mainly vinyl esters and/or alkyl esters of (meth)acrylic acid. Suitable esters are C ₁ of acrylic acid and/or methacrylic acid
~ _C14 , preferably _C1 - _C4 , alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl- and isopropyl (meth)acrylate, n-butyl- and isobutyl (meth)acrylate and 2-ethylhexyl (meth)acrylate. Suitable vinyl esters are the abovementioned vinyl esters of aliphatic or aromatic monocarboxylic acids, preferably vinyl acetate. Other suitable monomers are _C2 - _C4 alpha-olefins, such as ethylene, propylene and isobutylene, and optionally acrylic acid and methacrylic acid. If a transparent graft copolymer is not required, an aromatic vinyl compound such as styrene or α
-Methylstyrene, optionally mixed with (meth)acrylic ester, can also be used. Kraft polymerization reactions are carried out in solution or in bulk. Suitable solvents are hydrocarbons such as benzene, toluene, xylene, alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, t-butanol or their mixtures with water, chlorinated hydrocarbons. , for example chlorobenzene, methylene chloride, tetrachloroethylene, methyl acetate, ethyl or butyl acetate, and glacial acetic acid, or mixtures thereof. The graft base can be dissolved in the selected solvent system in a known manner. Of course, first a solution of one graft base is prepared, then the second polymer is dissolved in the resulting solution or in a solvent miscible with the first solvent, and then the two mixtures are combined. , and the homogeneous solution thus obtained can also be used for the grafting reaction. The graft polymerization reaction is preferably carried out in homogeneous phase, but in principle it can also be carried out in heterogeneous phase. It is also readily possible to first prepare a homogeneous phase from the graft base, vinyl monomer, disperse the resulting solution in water, and then, optionally after addition of a catalyst, carry out the polymerization reaction. Polymerization can be carried out continuously or batchwise. The grafting reaction can be carried out in the polymerization screw in the presence or absence of a solvent, and the graft polymerization mixture can be evaporated free of solvent or residual monomer in an evaporation screw, thin layer evaporator or spray dryer. The polymerization reaction is carried out at -20 to +250°C, preferably +30 to +250°C.
It is carried out at a temperature of +180° C. and under a pressure of from normal pressure to 300 bar, preferably up to 25 bar. The polymerization catalyst can be added to the polymerization mixture before, during or after the dissolution or mixing operation. The catalyst is preferably added to the reaction mixture after the preparation of the homogeneous graft base solution, together with the monomers or separately. The polymerization catalyst is preferably 0.001 to 2% by weight based on the total graft base and kraft monomer.
used in amounts of Of course, these quantities can be considerably exceeded. Suitable polymerization catalysts are per-compounds or azo-compounds or radical-forming highly substituted ethane derivatives, such as benzpinacol. Examples of suitable catalysts are: benzoyl peroxide, t-butyl perpivalate, lauroyl peroxide, t-peroctenoate.
-Butyl, t-butyl perbenzoate, di-t peroxide
-butyl, t-butyl perisononanoate, diisopropyl percarbonate, dicyclohexyl percarbonate, dicumyl peroxide, t-butyl perneodecanoate, azo-bis-isobutyronitrile or esters of azo-bis-isobutyric acid, e.g. Bis-ethyl ester. The initiator radicals can be generated by known redox systems or also by external radiation, actinic radiation or accelerated lightning. The monomers used during the polymerization reaction are grafted both onto the cellulose ester and onto the ethylene/vinyl ester copolymer and are cross-linked through the polymerized units of the monomers. form a union. This cross-linking has been demonstrated by polymer-analytical studies of graft polymers (see Example 1 in the experimental section). This novel cross-linking of starting materials that essentially tend to separate is a plausible explanation for the particularly high compatibility that graft copolymers have been found to exhibit. The mixture can be prepared in a known manner by dissolving the solution and working up by precipitation and drying or by evaporating the solvent through an evaporation screw, thin layer evaporator, tubular coil evaporator or spray dryer. The mixture can also be produced in melt form on a mixing roll, in a screw extruder or in a kneader. The molding compositions according to the invention can optionally also be modified with low molecular weight plasticizers. Suitable low molecular weight plasticizers include dimethyl phthalate,
Diethyl phthalate, triphenyl phosphate, methyl ethylene glycol phthalate, dibutyl sebacate, ethyl butylene glycol phthalate, butyl butylene glycol phthalate, dibutyl phthalate, dioctyl adipate, dioctyl phthalate, benzyl butyl phthalate, and triacetin. . Furthermore, the molding graft copolymers according to the invention may contain additives, such as for coloring and pigmenting the polymer mixture, for improving its stability against oxidation or light, or for reducing its flammability. It can contain The molding graft copolymers of ethylene/vinyl ester copolymers and graft copolymers of organic cellulose esters according to the invention exhibited a greatly increased notch impact strength measured according to DIN 53543. Furthermore, they are characterized by an improved dimensional stability against heat, measured as the bicut softening temperature, for example according to DIN 53460. Vikatsuto's softening temperature is 50°C higher than that of cellulose ester modified with a low molecular weight plasticizer.
up to high. Furthermore, the molding graft copolymers according to the invention exhibit improved mechanical properties with respect to these common cellulose ester molding graft copolymers;
For example, it shows an increase in hardness, tensile strength and elastic modulus. The known effect of so-called "plasticizer migration" has been demonstrated in graft copolymers of organic cellulose esters, ethylene/vinyl ester copolymers and vinyl monomers, or in mixtures of these graft copolymers with other organic cellulose esters. This type of moldable graft copolymer is particularly suitable for applications involving contact with foodstuffs, for example. The moldable graft copolymers according to the invention can be easily processed continuously or batchwise in known extruders and injection molding machines and exhibit good flow properties in this regard. Various molded products, acetate rayon, block acetate, film carriers for safety films,
Can produce electrically insulating films and lacquers. Due to the improved resistance of the products to hot air and aging, they can also be used for external finishing. The invention is illustrated by the following examples. In the examples, the percentages quoted always refer to percentages by weight. Example 1 Contains 900 g of cellulose acetopropionate containing 57.5% by weight propionic acid groups and 5.5% by weight acetate groups and 45% added vinyl acetate and has a Mooney viscosity of 20.
900g ethylene/vinyl acetate copolymer (EVA),
2500 g vinyl acetate, 13500 g t-butanol and 0.75 g t-butyl perpivalate under nitrogen, equipped with an anchor stirrer and equipment for adding various solutions, and controlling the internal temperature through a heating/cooling jacket system. 40 as carefully adjustable
Added to autoclave. The contents of the autoclave were heated to 70°C and then stirred at that temperature for 1 hour. Next, addition of the following two types of solutions was started. Solution 1: 5600g vinyl acetate Solution 2: 24g t in 4000g t-butanol
-Butyl perpivalate. Solutions 1 and 2 were added simultaneously over a period of 4 hours. The mixture was then stirred at 70°C for 3 hours and then at 80°C for 1 hour. Remove the mixture hot and add
500 g of a 5% solution of 2,6-di-t-butyl-p-cresol was added. The graft polymer was isolated by evaporative concentration in an evaporation screw.
The product had an intrinsic viscosity [η] of 0.96 [dl/g]. Its chemical composition was as follows; 12
% cellulose acetopropionate, 12%
EVA, 76% polymerized vinyl acetate units. Panels molded from this graft polymer at 170° C./200 bar pressure were very transparent, soft, flexible and showed no cracking under tensile stress. The glass transition temperature was measured at +23°C, which represented the main softening range of the sample. Another glass transition is observed at about −35° C., which may be associated with the EVA component. In order to study the structure of the graft polymer, the obtained graft product was subjected to fractionation. At the end of this, the product was fractionated at 25° C. using the separating liquid dimethylformamide/methylcyclohexane (1). The results are shown in the table below.

[Table] The lower phase contains ungrafted cellulose ester and ungrafted polyvinyl acetate, while the upper phase contains EVA and cellulose ester coupled with EVA via polymer crosslinking. are doing. Evaluating the analytical data obtained, it was found that 51% of the cellulose esters used were EVA via vinyl acetate cross-linking.
It was cross-bridged (coupled) with. (1) R. Kuhn's Makromol.Chem.177
(1976) 1525-1547. Example 2 2000 g t-butanol, 45% butyric acid groups and 19
300 g of cellulose acetobutyrate containing % acetate groups, 30 g EVA containing 45% added vinyl acetate, and 400 g vinyl acetate were heated to 70° C. under nitrogen. When a homogeneous solution was formed from these ingredients, a solution of 3 g of t-butyl perpivalate in 1000 g of t-butanol was added over a period of 2 hours. Then at 70℃ for 2 hours.
Next, the mixture was stirred at 80°C for 1 hour. The volatile fractions were then stripped in an evaporation screw. The graft copolymer was glass clear and could be processed to produce a dry elastic film. The intrinsic viscosity [η] measured in tetrahydrofuran reached 0.82 [dl/g]. The composition of the graft polymer was as follows: 30.5% EVA, 30.5% cellulose acetobutyrate, 39% polymerized vinyl acetate units. The graft polymer was subjected to shear modulus measurements (measurement frequency, approximately 1 Hz). The following glass transition temperatures were observed: _Tg1 = -32°C (pure EVA, about -25°C), _Tg2 = +27°C (polyvinyl acetate phase) and _Tg3 = about 65°C. Example 3 2000 g t-butanol, 500 g water, 300 g cellulose acetobutyrate, 300 g EVA containing 45% added vinyl acetate and 600 g
g of vinyl acetate were heated to 80° C. in 6 reactors. 4.5 g of t-butyl perpivalate in 1000 g of t-butanol was added to the homogeneous solution over a period of 3 hours. The mixture was then stirred for 1 hour. The volatile fractions were stripped in an evaporator screw. The product is
It had an intrinsic viscosity [η] of 0.84 [dl/g] and contained 26% EVA, 26% cellulose acetobutyrate and 48% polymerized vinyl acetate units. Molded panels made from the product were soft, flexible, and transparent. Example 4 100 g of cellulose acetobutyrate, 1500
To a solution consisting of 100 g EVA and 900 g ethyl acrylate containing 45% added vinyl acetate in 1 g t-butanol. The graft copolymer was isolated by precipitation in hot water.
1038 g of grafted product consisting of 9.25% EVA, 9.25% cellulose acetobutyrate and 81.5% polymerized ethyl acrylate units was obtained after drying. The intrinsic viscosity [η] in tetrahydrofuran reached 1.31 [dl/g]. Example 5 Using a two-part reactor (two 2-reactors) for continuous polymerization, the polymerization was carried out for 70 minutes according to the following steps.
The reaction temperature was 0.degree. The following solutions were added to the first reactor per hour. Solution 1: 0.221Kg of cellulose acetobutyrate, 0.442Kg of EVA containing 45% added vinyl acetate, 0.354Kg of vinyl acetate, and 2.482Kg of t-butanol. After an average residence time of 40-45 minutes in the first reactor and after reaching an average monomer conversion of about 85%, the polymer syrup was added to the second reactor.
The average residence time in the second reactor was about 40 minutes. Monomer conversion after leaving the second reactor was virtually 100%. The polymer syrup was processed in a distillation screw. The grafted product had an intrinsic viscosity [η] of 1.65 [dl/g] and consisted of 11.1% cellulose ester, 22.2% EVA and 66.7% polymerized vinyl acetate units. The product could be processed to produce highly transparent, durable and elastic moldings. Example 6 2.25 g t-butyl perpivalate and 200 g t-butanol in 50 g vinyl acetate at 75° C. for 2 hours to prepare EVA containing 150 g 45% added vinyl acetate. , to a solution consisting of 500 g of cellulose acetopropionate, 150 g of vinyl acetate and 2000 g of t-butanol. Thereafter, the mixture was stirred at 75°C for 2 hours. The grafted product was isolated by precipitation in water, the volatile fractions were stripped, and the polymer was dried. The grafted product contained 19% EVA, 63% cellulose acetopropionate, and 18% polymerized vinyl acetate units. The intrinsic viscosity [η] reached 1.2 [dl/g] in tetrahydrofuran. Example 7 14200g t-butanol, 2130g EVA containing 45% added vinyl acetate, 2130
g of cellulose acetopropionate and 800 g
A solution consisting of vinyl acetate was heated to 70°C in a 40°C autoclave. A solution consisting of 7100 g t-butanol, 975 g vinyl acetate and 21.4 g t-butyl perpivalate was then added over 2 hours, followed by stirring at 80° C. for 1 hour. 15 g of 2,6-di-tert-butyl-p-cresol were then added to the mixture, after which the volatile fractions were removed in an evaporating screw. The resulting graft polymer was 1.6
It had an intrinsic viscosity [η] of [dl/g] and contained 35.25% EVA, 35.25% cellulose acetopropionate and 29.5% polymerized vinyl acetate units. Example 8 A solution of 2.25 g t-butyl perpivalate in 200 g t-butanol was heated at 70° C. for 2 hours.
In, 500 g of cellulose acetobutyrate,
150g EVA containing 45% added vinyl acetate, 150g vinyl acetate and 200g t-
It was added into a solution consisting of butanol. Next, the mixture was stirred at 70°C for 5 hours. The grafted product was isolated by precipitating the solution in water, washed with water on a roll, and dried at 70°C in a vacuum drying vessel. The product has an intrinsic viscosity [η] in tetrahydrofuran of 1.46 [dl/g] and contains 18.5% EVA, 62.5% cellulose acetobutyrate and 19% polymerized vinyl acetate units. Was. From grafted product (170℃/200
The molded panels produced (at pearl pressure for 20 minutes) were clear, flexible, and showed no cracking under bending and tensile stress. The following glass transition was observed during shear modulus measurements on this formed panel (measurement frequency,
1 Hz): Tg ₁ = -27°C (EVA), Tg ₂ = 52°C (mixed phase of cellulose ester and EVA coupled with vinyl acetate), Tg ₃ = +95°C (cellulose acetobutyrate). Example 9 300 g of EVA containing 45% added vinyl acetate, 300 g of cellulose acetate containing 54% of acetic acid groups and 800 g of methyl acrylate were reacted with 2000 g of dioxane in 6 reactors. It was heated to 80°C in a chamber. A solution of 4.5 g of t-butyl perpivalate in 1000 g of dioxane was then added to
added over time. After stirring for 1 hour, 5
g of 2,6-di-t-butyl-p-cresol was added to the mixture, after which the grafted product was isolated by precipitation. The grafted product has an intrinsic viscosity [η] in THF of 0.58 [dl/g], and
27.6% cellulose acetate 27.6% EVA and 44.8%
It consisted of polymerized methyl acrylate units. The grafted product was identified by polymer analysis in the same manner as described in Example 1.
The results showed that 44% of the cellulose acetate used was coupled with the EVA polymer via methacrylate crosslinking. Example 10 In a 40 reactor, 0.75 g of t-butyl perpyvarade was added to 900 g of cellulose acetopropionate, 900 g of EVA containing 45% added vinyl acetate, 2500 g of vinyl acetate and
In addition to a solution consisting of 13,500 g of t-butanol,
It was then heated to 70°C. The solution described below was then added over a period of 4 hours. Solution 1: 5600 g vinyl acetate, 400 g ethylene from pressure vessel Solution 2: 24 g t- in 4000 g t-butanol
Butyl perpivalate After further stirring for 3 hours at 70° C., 25 g of 2,6-di-t-butyl-p-cresol were added to the mixture, which was then processed in an evaporation screw. The reaction product has an intrinsic viscosity [η] of 1.02 [dl/g], and
It consisted of 9.95% EVA, 9.95% cellulose acetopropionate, 3.5% polymerized ethylene units and 76.6% polymerized vinyl acetate units. Example 11 1575g cellulose propionate, 4680g
Contains 45% added vinyl acetate
A solution consisting of EVA, 1000 g vinyl acetate and 13500 g t-butanol was heated to 110° C. in a 40 reactor. A solution consisting of 1700 g vinyl acetate, 15 g benzoyl peroxide and 4000 g t-butanol was then added over 3 hours, followed by stirring at 110° C. for 3 hours. 18 g of 2,6-di-tert-butyl-p-cresol were added to the mixture, which was then processed in an evaporating screw. Vinyl acetate conversion rate is
It reached 96%. Graft copolymer has 52.9%
It consisted of EVA, 17.8% cellulose acetopropionate and 29.3% polymerized vinyl acetate units. It had an intrinsic viscosity [η] of 1.38 [dl/g]. By the method of Example 1, a graft copolymer having the composition shown in Table 1 below was produced.

【table】

[Table] Preparation of mixtures Examples 22 to 32 Cellulose acetobutyrate containing 45% of butyric acid groups and 19% of acetic acid groups was prepared on a mixing roll at 170°C in the amounts indicated in Table 2. and the graft copolymer, where the sum of both components reached 100%. Test specimens were prepared by granulating the rough sheets and then injection molding at a melt temperature of 230°C. The symbols used in Tables 2 and 3 have the following meanings: a _o = Impact strength according to DIN 53453, [Kj/m ² ] a _k = Notch impact strength according to DIN 53453, [Kj/m ² ] Bicut = DIN53460, method B, force 49.05 [N]
Softening temperature according to °C H _k 30 = ball identification hardness after 30 seconds according to DIN 53456, [N/mm ² ].

[Table] Examples 33-40 Cellulose acetopropionate containing 57.5% propionic acid groups and 5.5% acetate groups was mixed on a mixing roll at 170°C in the amounts shown in Table 3. Mix intensively with the graft polymer, where the sum of the components reached 100%. The coarse sheet was granulated and then injection molded at a melt temperature of 230°C.

【table】

【table】

Claims (1)

[Claims] 1. Essentially: (1) (a) an ethylene/vinyl ester copolymer containing from 25 to 55% by weight of added vinyl ester, as determined by light scattering; 20 to 95% by weight having a molecular weight of 40,000 to 1,000,000, and (b) one or more aliphatic C ₁ to
C ₅ - Cellulose ester of carboxylic acid with a relative viscosity of 2% by weight in acetone.
(2) one or more vinyl esters;
and/or polymerized repeating units of alkyl esters of acrylic acid and/or methacrylic acid 85
and (3) 0 to 20% by weight of polymerized repeating units of one or more C ₂ -C ₄ α-olefins of ethylene/vinyl ester copolymers and cellulose esters. at least in part are crosslinked to each other via polymerized repeat units of the graft monomers, and the sum of components (1) to (3) and (a) and (b)
A thermoplastic molding graft copolymer in which the sum of 100% by weight and the intrinsic viscosity in tetrahydrofuran range from 0.4 to 2.5. 2 Essentially: (1) (a) an ethylene/vinyl acetate copolymer containing from 25 to 55% by weight of added vinyl acetate and having a molecular weight as determined by light scattering;
40,000 to 1,000,000, and (b) one or more aliphatic C ₁ to
C ₅ - Cellulose ester of carboxylic acid with a relative viscosity of 2% by weight in acetone.
15 to 85% by weight of a graft base consisting of 80 to 5% by weight of 2.5 to 6.0; and (2) one or more of vinyl acetate and/or acrylic acid and/or methacrylic acid.
from 85 to 15% by weight of polymerized repeating units of _C1 - _C4 -alkyl esters, and (3) from 0 to 20% by weight of polymerized repeating units of one or more _C2 - _C4 alpha-olefins. The thermoplastic molding graft copolymer according to claim 1, wherein the total of components (1) to (3) and the total of (a) and (b) each reach 100% by weight. 3 Essentially () one or more aliphatic C ₁
~ _C5 - cellulose ester of carboxylic acid with a relative viscosity of 2% by weight in acetone of 2.5
~6.0% by weight and () consisting essentially of (1) (a) an ethylene/vinyl ester copolymer containing 25 to 55% by weight of added vinyl ester; Molecular weight measured by scattering method is 40,000 to 1,000,000
20-95% by weight, and (b) one or more aliphatic C ₁
~ ₁₅ to 85% by weight of a graft base consisting of 80 to 5% by weight of a cellulose ester of C5-carboxylic acid having a relative viscosity of 2.5 to 6.0 at 2% by weight in acetone, and (2) 1 type. 85 to 15% by weight of polymerized repeating units of vinyl esters and/or alkyl esters of acrylic acid and/or methacrylic acid; and (3) one or more _C2 - _C4 alpha-olefins. 50 to 1% by weight of a graft copolymer consisting of 0 to 20% by weight of polymerized repeating units, wherein at least a portion of the ethylene/vinyl ester copolymer and the cellulose ester in component is crosslinked through polymerized repeating units and is the sum of components () and (), the sum of (1) to (3), and (a) and (b).
The thermoplastic molding graft copolymer according to claim 1, wherein the sum of the amounts of each amount is 100% by weight. 4. As component (), essentially: (1) (a) an ethylene/vinyl acetate copolymer containing 25 to 55% by weight of added vinyl acetate, with a molecular weight determined by light scattering; but
40,000 to 1,000,000, and (b) one or more aliphatic C ₁ to
C ₅ - Cellulose ester of carboxylic acid with a relative viscosity of 2% by weight in acetone.
15-85% by weight of a graft base _consisting of 80-5% by weight _of 2.5-6.0; (3) 0 to 20% by weight of polymerized repeating units of one or more C ₂ -C ₄ α-olefins; The graft copolymer for thermoplastic molding according to claim 3, which contains a graft polymer in which the total amount and the total amount of (a) and (b) each reach 100% by weight. 5. The thermoplastic molding graft copolymer according to any one of claims 1 to 4, which contains cellulose acetate, cellulose acetobutyrate, cellulose acetopropionate, or a mixture thereof as a cellulose ester. .