DE2526177A1 - Soluble copolyester from terephthalic acid, isophthalic acid - and satd. aliphatic diacid with ethylene glycol and neopentyl glycol, in specified ratio, as adhesive, coating, softener and binder - Google Patents

Abstract

A copolyester contains (a) terephthalic acid, (b) isophthalic acid, (c) an acid of formula HOOC- (CH2)n-COOH, where n = 4-7, (d) ethylene glycol and (e) neopentyl glycol. The molar ratios are : (a+b):c = 50:50-75:25 (55:45-65:35) a:b = 30:70-70:30; d:e = 40:60-80:20 (40:60-50:50). The copolyester is an adhesive, coating, softener or binder. The adhesives are esp. used to bond synthetic films and metal films. The copolymers are soft, are sol, in many organic solvents, have adequate mechanical and thermal properties, and have low melt and soln. viscosity. Pref. molar ratios are : a:b:c = 15-52.5 : 15-52.5:25-50 (16-45: 16-45: 35-45), more esp. 25-35: 25-35: 35-45. Adipic acid is pref. as component (c). Typically, a copolyester prepd. from 0.562 moles dimethyl terephthalate, 0.562 moles dimethyl isophthalate, 2.88 moles ethylene glycol, 1,24 moles neopentyl glycol and 0.748 moles adipic acid had intrinsic viscosity 0.65 and was. sol. in ethyl acetate, methyl ethyl ketone and toluene.

Description

Copolyesters and Process for Their Preparation The invention relates to Copolyesters and a process for their preparation, in particular copolyesters, the for adhesives, paints, surface treatment agents, plasticizers, Binders and the like are suitable and a method for their preparation.

Aromatic polyesters such as polyethylene terephthalate have excellent mechanical properties, thermal properties, chemical properties and electrical properties and are therefore widely used for manufacture of fibers, foils, molded parts, etc.

Like. Used. However, these common aromatic polyesters have have poor softness and are also found in many common organic solvents insoluble and only in very few solvents, e.g. solvent mixtures Phenol and tetrachloroathane, trifluoroacetic acid and the like only soluble by heating. It is thus very difficult to find these usual aromatic polyester For adhesives, paints, WeicilmacE-Ier, Oerflcenbehandlungsmitel, binders and the like. To improve the properties of the aromatic polyester and to make them suitable for the aforementioned purposes, attempts have been made to aliphatic dicarboxylic acids and / or other glycol components of the copolymerization to submit to the formation of aromatic polyester.

However, if aliphatic dicarboxylic acids and / or other glycol components copolymerized to give the aromatic polyesters the desired softness and to impart solubility in organic solvents, polyesters are used obtained poor mechanical and thermal properties. Polyester with very good softness and solubility in common organic solvents as well with excellent mechanical and thermal properties that make it practical Making use suitable are thus unknown.

In-depth investigations by the applicant with the aim of copolyester produce the excellent softness and solubility in common organic Solvents as well as excellent mechanical ones sufficient for practical use and thermal properties and have low melt and solution viscosity and for adhesives, paints, plasticizers, surface treatment agents, Suitable binders and the like have found copolyesters with these properties Can be made by using a special combination of carboxylic acids (terephthalic acid or its derivatives, isophthalic acid or its derivatives and certain aliphatic Dicarboxylic acids) and a certain combination of glycols (e.g. ethylene glycol and neopentyl glycol) is copolymerized.

The invention accordingly relates to copolyesters, which are suitable for adhesives, Paints, surface treatment agents, plasticizers, binders and the like.

suitable, and a process for making these copolyesters, the excellent softness and solubility in common organic. Solvents as well as have excellent mechanical and thermal properties.

According to the invention, the desired copolyesters are produced, adding the following five components: a) terephthalic acid or an ester-forming one Derivative of terephthalic acid, b) isophthalic acid or an ester-forming derivative of isophthalic acid, c) an aliphatic dicarboxylic acid of the formula HOOC- (CH2) n-COOH, in which n is an integer from 4 to 7, or an ester-forming derivative thereof Dicarboxylic acid d) ethylene glycol and e) neopentyl glycol in the usual way in one are copolymerized in such a proportion that the five components in the copolyester are contained in the following molar ratio: 50/50 (b)] / (e) 75/25 30/70 C (a) / (b) # 70/30 40/60 # (a) / (e) # 80/20.

As ester-forming derivatives of terephthalic acid are suitable for Purposes of the invention dimethyl terephthalate, Diethyl terephthalate, Dipropyl terephthalate, dibutyl terephthalate, diphenyl terphthalate, terephthalic acid dichloride etc.

As ester-forming derivatives of isophthalic acid are suitable for Purposes of the invention, for example, dimethyl isophthalate, diethyl isophthalate, dipropyl isophthalate, Dibutyl isophthalate, diphenyl isophthalate and isophthalic acid dichloride.

As aliphatic dicarboxylic acids of the formula HOOC- (CH2) n-COOH, in which n is an integer from 4 to 7, for example adipic acid, pimelic acid, Suberic acid and azelaic acid in question. Of these, adipic acid is the most suitable. as Ester-forming derivatives of aliphatic dicarboxylic acids are esters of aliphatic Dicarboxylic acids, e.g. the dimethyl ester, diethyl ester, dipropyl ester, dibutyl ester, Diphenyl ester or the dichloride.

Copolyesters are known which are made using sebacic acid as aliphatic dicarboxylic acid (GB-PS 1 118 538 and DT-OS 1 522 636). However, if sebacic acid or dodecanedioic acid instead of the aliphatic acid used for the purposes of the invention show the copolyesters produced poor anti-blocking properties when coated on films or sheets will. On the other hand, if succinic acid or glutaric acid instead of the aliphatic Dicarboxylic acid used for the purposes of the invention undergoes severe pyrolysis takes place during the polycondensation reaction in the melt at high temperature, so that the desired polyesters, which are suitable for adhesives, paints, etc. cannot be produced.

The copolyesters according to the invention contain the five components (a), (b), (c), (d) and (e) in molar ratio 50/50 # [(a) + (b)] / (c) ffi75 / 25 30 / 70- ffi (a) / (b) # 70/30 40/60 # (a) / (e) # 80/20, preferably 55/45 # [(a) + (b)] / (c) # 65/35 30/70 # (a) / (b) L 70/30 40/60 # (d) / (e) # 80/20.

In other words, the molar ratio dc of the constituents is (a) / (b) / (c) 15 to 52.5 / 15 to 5S, 5/25 to 50, preferably 16 to 45/16 to 45/35 to 45, # and the molar ratio of (d) / (e) is 40-80 / 20-60. When the molar ratio of Sunme of components (a) and (b) to component (c) in the copolyester, i.e. / (a) + (h) // (c) is above 75:25, the copolyesters obtained are rigid and have poor flexibility and poor mechanical properties. If on the other hand the molar ratio is below 50:50, the copolyesters obtained show a lower one Cohesive force as well as lower adhesion and heat resistance.

When the molar ratio of component (a) to component (b) in the copolyester is above 70:30, the copolyesters obtained have poor solubility in organic solvents and a lower solution stability. If on the other hand this molar ratio is below 30: 70, the copolyesters obtained show poor results thermal and mechanical properties.

When the molar ratio of component (d) to component (e) in the copolyester is above 80:20, the copolyesters obtained have a poorer solubility in common organic solvents and a extremely low Solution stability. On the other hand, if this molar ratio is below 40:60, have the copolyesters get lower melting points and poor mechanical properties.

Particularly well suited of the copolyesters produced according to the invention are those containing the terephthalic acid residue, the isophthalic acid residue and the adipine-oure residue in a molar ratio of 25-35 / 25-35 / 35-45 and the ethylene glycol residue and neopentyl glycol residue The copolyesters according to the invention contain in a molar ratio of 50-60 / 40-50 the desired excellent properties can only be achieved through copolymerization of the five components in the prescribed molar ratio. if one of the components is not used in an amount which corresponds to the molar ratio of the five components in the prescribed range can be the desired Copolyester cannot be produced.

In the context of the invention, the copolymerization is carried out according to a customary one Process carried out, for example, by preparing the esters of the glycols with the acids by direct esterification of the acids and glycols or by transesterification the carboxylic acid alkyl ester and the glycols and subsequent copolymerization of the products obtained by a process suitable for the manufacture of polyesters is common, e.g. by melt polymerization or by polymerization in solid phase. It is also possible to produce the copolyester by depolymerization, by heating polyester (e.g. polyethylene terephthalate) with glycols or acids and then copolymerizing the products obtained with acids or glycols will.

In the method according to the invention, in addition to the above, five components additional components can be used. As a further compo Nents are suitable, for example, trifunctional or higher-functional glycols or acids such as glycerin, pentaerythritol, trimellitic acid and pyromellitic acid, the be used in such an amount that the desired properties of the copolyester not be worsened. In order to accelerate the reaction, various Usual catalysts for esterification, transesterification or polycondensation reactions are common. You can also depend on the desired Properties of the products, various modifying agents, stabilizers.

lizers and / or pigments are used.

The copolyesters made according to the invention have excellent properties thermal and mechanical properties, very good adhesive strength, solubility in solvents and solvent stability. They are particularly excellent in relation on solubility in solvents and solution stability and can therefore be used for the can be used for the various purposes listed below.

When the copolyester according to the invention is used for solution adhesives they are dissolved in an organic solvent. As a solvent. are for example benzene, toluene, acetone, chloroform, ethyl acetate, n-butyl acetate, Dioxane, tetrahydrofuran, cyclohexanone, methyl ethyl ketone and phenol alone or in Mixture.

When used for hot melt adhesives, the copolyesters are according to Invention very advantageous because they have a lower melt viscosity than the common polyesters used for hot melt adhesives. For use the copolyester according to the invention as a hot melt adhesive can be used after yer j seemed methods to be done. The most suitable method will be according to the type of bonding and depending on the objects to be bonded chosen. For example, the copolyesters can come in a wide variety of forms. e.g. in the form of powders, schnitzel, granules, ribbons, cords or foils, to be brought.

The molded product is placed between the objects to be glued inserted, and the whole is brought to a temperature above the softening point of the copolyester is heated to bond the objects together. It is also possible to melt the copolyester and the melted copolyester beforehand to apply the objects to be glued and to cool, whereupon the objects heated at any time to bond them together. aside from that can be used to increase the heat resistance and solvent resistance of the bonded Products Means capable of forming a three-dimensional structure in the copolyester, e.g., isocyanate compounds, epoxy compounds and aziridyl compounds, while of the bonding process, whereby the copolyester is crosslinked.

When the copolyester according to the invention is used as adhesives is the type of materials or the shape of the objects to be bonded unlimited. The copolyesters according to the invention are particularly advantageous for Bonding of various plastic films and metal foils.

The copolyesters according to the invention can also be used as surface treatment agents can be used for glass fibers or foils. To do this, the copolyesters are in the form a solution in a solvent. The copolyesters are also suitable according to the invention as a means for preventing the shrinkage of unsaturated th Polyesters, as surface smoothing agents, plasticizers for thermoplastic Masses (e.g. polyvinyl chloride and polyacrylates) or as binders for metal oxides for coating substrates and sub-bases.

The invention is further illustrated by the following examples. The values of the intrinsic viscosity [@] mentioned in these examples were in one Mixture of phenol and symmetrical tetrachloroethane (weight ratio 60:40) measured at 30 ° C. The stated melting points were determined using a micro-melting point apparatus (Manufacturer Yanagimotò Seisakusho) measured the temperature at a rate is increased by 1 ° C / minute.

The abbreviations used in the examples have the following Meanings: TPA: terephthalic acid IPA: isophthalic acid EG: ethylene glycol NPG: neopentyl glycol DEG: Diethylene glycol j Example 1 In a 1 l autoclave, 0.562 mol of dimethyl terephthalate, 0.562 mol of dimethyl isophthalate, 2.88 mol of ethylene glycol, 1.24 mol of neopentyl glycol, 118 mg zinc acetate dihydrate (as a transesterification catalyst) and 246 my antimony trioxide (as a polycondensation catalyst).

The mixture is heated to 160 to 210 ° C. for transesterification. After a Heating time of about 2 hours, the theoretical amount of methanol is distilled off and thereby terminates the transesterification reaction. The reaction mixture becomes a low narrow trimethyl phosphate added. The mixture is heated to 200 for 30 minutes with stirring heated to 2100C. After increasing the Ternpera ture to be at 2200C 109.4 g (0.7483 mol) of adipic acid were added to the mixture, whereupon the mixture was subjected to esterification Is heated to 220 to 230 ° C for 30 minutes.

The temperature is then increased to 2500C.

At the same time, the pressure in the autoclave is gradually reduced, whereupon the excess glycol is distilled off at 2500C and 10 mm Hg. The temperature continues to increase to a final value of 2700C and at the same time the pressure on lowered a final value of 0.3 mm Hg, followed by 2 hours of polymerization reaction is subjected to a colorless polymer (1) with an intrinsic viscosity }? 7 is obtained from G, 65.

In the above-described quietly different polymers (2 to 7) produced. All products have an intrinsic viscosity of more than 0.60.

The solubility of these polymers in various solvents Wil be inspected. The results are given in Table 1.

Table 1 Per- duct polymer component (molar ratio) melt solubility Point, ° C methyl ethyl Acid residue glycol residue ethyl acetate ketone toluene 1 TPA 31 IPA 31 EG 59 60 soluble soluble soluble Adipine- 38 NPG 41 acid 2 TPA 30 IPA 20 EG 65 40 soluble soluble soluble Adipine- 50 NPG 35 acid 3 TPA 35 IPA 30 EG 60 66 soluble soluble soluble Adipine- 35 NPG 40 acid 4 TPA 31 IPA 31 EG 60 60 soluble soluble soluble Adipine- 38 NPG 40 acid 5 TPA 31 IPA 31 EG 60 61 soluble soluble soluble Adipine- 38 NPG 40 acid 6 TPA 31 IPA 31 EG 58 61 soluble soluble soluble Adipine- 38 NPG 42 acid 7 TPA 20 IPA 45 EG 60 45 soluble soluble soluble Adipine- 25 NPG 40 acid Example 2 The polymers (1-7) prepared according to Example 1 are dissolved in a solvent mixture of toluene and methyl ethyl ketone (weight ratio 20:80) in such an amount that 40% strength solutions are obtained. These solutions are held at OC. Even after more than 70 days, the solutions are clear and consistent. They can be stored unchanged without gel formation.

F'e's2iel 3 The polymers prepared according to Example 1 (1 - 7); are each dissolved in methyl ethyl ketone in such an amount that 40% Solutions are obtained.

These solutions are each on one side of a polyester film (biaxially oriented film made of polyethylene terephthalate, manufactured by the applicant, Thickness 19 µ) and an aluminum foil (degreased product "AIH-O", manufacturer Nippon Seihaku K.K., thickness 50 µ) and then dried for 15 minutes at 850C. on the polyester film becomes an uncoated polyester film and on top of the aluminum foil laid an uncoated aluminum foil. The thickness of the adhesive resin layer is 4 / u. The superimposed films are 10 seconds at 1000C under a pressure 2 of 4 kg / cm glued together. The samples obtained are 1 cm wide Samples cut on which the force or tear-off force required to separate after the T tear-off test at 20 ° C with a tensile testing machine (Tensilon, manufacturer Toyo Sokuki K.K.) measured at a speed of the pulling clamp of 10 cm / minute will. The results are shown in Table 2 below.

Table 2 Product T tear-off force (g / cm) No. 19 µ polyester film / 50 µ aluminum foil / 19 µ polyester film 50 µ aluminum foil 20 ° C 65 ° C 20 ° C 65 ° C 1 70 320 305 340 2 55 3 60 5 3 50 360 230 # 400 4 95 305 320 330 5 100 340 340 365 6 115 345 365 380 7 60 10 - - Example 4 The polymers (8 to 11) mentioned in Table 3 below are prepared in the manner described in Example 1.

Table 3 Polymer component melting limit viscosity Product (molar ratio) point viscosity No. Acid residue Glycol residue (° C) [#] 8 TPA 35 IPA 30 EG 60 66 0.73 Adipine- 35 NPG 40 acid 9 TPA 35 IPA 30 EG 60 64 0.72 Adipine- 35 NPG 40 acid 10 TPA 35 IPA 30 EG 60 67 0.76 Adipine- 35 NPG 40 acid 11 TPA 35 IPA 30 EG 60 68 0.75 Adipine- 35 NPG 40 acid These polymers (8 to 11) are each dissolved in methyl ethyl ketone in such an amount that 13% strength solutions are obtained. These solutions are applied in a thickness of 0.1 mm to one side of a polyethylene terephthalate film (thickness 19 μ) and then dried thoroughly for 20 minutes at 80 ° C. and 35 mm Hg. Another polyethylene terephthalate film (thickness 19 / u) or an aluminum film (thickness 50 μ) is placed on the coated side. The laminates are subjected to a static load of 22 g / cm @ and kept for 69 hours at 22 ° C. in an atmosphere with 55% relative humidity. The laminates obtained in this way are cut into strips 2.0 cm wide. These strips are used to measure the force or tear-off force required for separation after the T tear-off test at 220 ° C. with a tensile tester (CTensilon) at a speed of the pulling clamp of 10 cm / minute in order to determine the anti-blocking property of the products. The results are shown in Table 4 below.

Table 4 T tear-off force (g / cm) product No. polyester film / polyester film; Polyester foil aluminum foil 8 8 10 9 9 25 10 r 40 11 10 65 The products with the lower T-k tensile strength have better antiblocking properties.

Comparative Example 1 In the manner described in Example 1 are the polymers listed in Table 5 (1 'to 3') were produced. The solubility these polymers in various solvents is determined. The results are listed in Table 5.

Table 5 product No. Polymer Component (Molar Ratio) Melt Solubility point, ° C methyl ethyl Acid residue glycol residue ethyl acetate ketone toluene 1 'TPA 65 EG 55 Adipine- 35 NPG 45 61 insoluble insoluble insoluble acid 2 'TPA 46 little IPA 19 EG 58 50 insoluble soluble insoluble Adipine- 35 DEG 42 (10%) acid 3 'TPA 26 IPA 39 EG 100 59 insoluble insoluble insoluble Adipine- 35 acid COMPARATIVE EXAMPLE 2 The polymers 4 'and 5' mentioned in Table 6 are produced in the manner described in Example 1.

Table 6 Product polymer component melt Grcnzis no. (Molar ratio) point, viscosity acid residue glycol residue ° C [#] 4 'TPA 68 EG 58 Adipin- NPG 42 65 0.64 acid 32 5 'TPA 70 EG 50 Azelain- NPG 50 66 0.63 acid 30 The polymers 4' and 5 'are each in a solvent mixture of toluene and methyl ethyl ketone (Weight ratio 20:80) dissolved in such an amount that 40% solutions are obtained will. These solutions are kept at 40C. White, insoluble, low molecular weight Solids swell in the solution of the polymer 5 'or are precipitated, whereby the transparency of the solution is considerably impaired. If the solution of the polymer is left to stand for 4 '10 days, it gels and becomes gel-like.

Comparative Example 3 In the manner described in Example 1 are the polymers 6 'to 9' mentioned in Table 7 were produced.

In the manner described in Example 3, these polymers each dissolved in methyl ethyl ketone. These solutions are each on a page a polyester film and an aluminum foil applied and then dried. on the polyester film becomes a polyester film not coated with adhesive and an aluminum foil not coated with adhesive is placed on the aluminum foil. The film pairs obtained are the Subject to contact bonding. The samples obtained in this way are cut into strips 1 cm wide.

The force or tear-off force required for separation is applied to these strips using the T tear-off test with a tensile testing machine (Tensilon, manufacturer Toyo Soki K.K.) at 200C and a pulling clamp speed of 10 cm / minute measured. The results are given in Table 7.

Table 7 Product polymer component T tear-off force (g / cm) No. (molar ratio) 19 µ polyester film / 50 µ aluminum foil / Acid residue Glycol residue 19 µ polyester film 50 µ aluminum film 6 'TPA 50 EG 60 5 4 IPA 50 NPG 40 7 'TPA 59 IPA 32 EG 55 2 3 Adipine- 9 NPG 45 acid 8 'TPA 20 IPA 10 EG 55 3 5 Adipine- 70 NPG 45 acid 9 'TPA 32 IPA 18 EG 20 2 4 Adipine- NPG 80 acid 50 COMPARATIVE EXAMPLE 4 The polymer 10 'mentioned in Table 8 is produced in the manner described in Example 1. It has a melting point of 65 C and a viscosity r of 0.69.

In the manner described in Example 4, a solution of the polymer is obtained 10 'in methyl ethyl ketone on one side of a 19 / u thick polyethylene terephthalate film applied and then dried. Another layer is placed on top of the applied layer Polyethylene terephthalate foil (thickness 19 / u) or an aluminum foil (50 µ) placed, whereupon the pairs of foils are left lying. The laminates obtained in this way are cut into strips 2.0 cm wide.

The tear-off force is measured on these strips with the aid of the T-tear-off test with a tensile testing machine "Tensilon" at 22 ° C and a pulling speed Clamp measured at 10 cm / minute to determine the antiblocking property of the products determine. The results are in the table; 8 called.

Table 8 Product | Polymer component T tear force, g / cm No. (molar ratio) polyester- polyester- Acid residue glycol residue film / poly film / aluminum ester foil nium foil 10 'TPA 35 IPA 30 EG 60 18 # 120 Seba- NPG 40 a- acid 35 Insertion page -20a- Example 5 The polymers 12 to 15 mentioned in Table 9 are prepared in the manner described in Example 1.

The solubility of these polymers in various solvents (Ethyl acetate, methyl ethyl ketone and toluene) is determined. All polymers are easily soluble in these solvents.

As can be seen from the results in Tables 4 and 8, the prepared using aliphatic dicarboxylic acids according to the invention Polymers 8 to 11 have a lower T-tear force, i.e. much better anti-blocking properties compared to polymer 10 made with sebacic acid Further the polymers 12 to 15 are each in a solvent mixture of toluene and ethyl ethyl ketone (weight ratio 20:80) dissolved in such an amount, that 40% solutions are obtained. These solutions are kept at 4 ° C. the Solutions are still clear even after 70 days and can be stored without gel formation.

In addition, the polymers 12 to 15 are based on those described in Example 3 Way each dissolved in methyl cithyl ketone. The solutions obtained are on a Side of a polyester film applied and then dried. On the polyester films obtained a polyester film not coated with the polymer bæw. one not placed with polymer coated aluminum foil, whereupon the foil pairs of the contact bonding be subjected. The samples obtained in this way become strips 1 cm wide cut. The tear-off force on these strips after the T-tear test is below Use of a tensile testing machine "Tensilon" at 65 C and a speed of pulling clamp measured at 10 cm / minute. The results are given in Table 9.

Table 9 Polymer component T tear-off force Product (molar ratio) (g / cm) No. polyester film / Acid residue, glycol residue, polyester film TPA 55 12 IPA 10 EG 50 450 Adipine- 35 NPG 50 acid TPA 45 13 IPA 20 EG 50 400 Adipine- 35 NPG 50 acid TPA 33 14 IPA 32 EG 50 350 Adipine- 35 NPG 50 acid 15 TPA 20 IPA 45 EG 50 50 Adipine- 35 NPG 50 acid COMPARATIVE EXAMPLE 5 The experiment described in Example 5 is repeated with the difference that the amounts of the terephthalic acid component and the isophthalic acid component are changed, the polymer sate 11 'to 13' mentioned in Table 10 being obtained.

Table 10 Polymer component Product (molar ratio No acid residue, glycol residue 11 'TPA 65 IPA 0 EG 50 Adipine- 35 NPG 50 acid 12 'TPA 65 IPA 0 EG 50 Adipine- 35 NPG 50 acid 13 'TPA 65 IPA 0 EG 50 Adipine- 35 NPG 50 acid The polymers 11 'to 13' are each dissolved in a solvent mixture of toluene and methyl ethyl ketone (weight ratio 20:80) in such an amount that 490% strength solutions are obtained. These solutions are kept at 4 ° C. White, insoluble, low molecular weight solids float in the solution of the polymer 11 'or are precipitated, as a result of which the transparency of the solution is significantly impaired.

Furthermore, these polymers are based on those described in Example 3 Each track was dissolved in methyl ethyl ketone.

The solutions obtained are on one side of a polyester film and an aluminum foil and then dried. On the polyester film is a polyester film not coated with polymer and on the aluminum foil an aluminum foil not coated with polymer is placed. The slide pairs are then subjected to contact bonding. The samples obtained in this way are Cut strips 1 cm wide.

The tear-off force is measured on this strip using a tensile testing machine (Tensilon) at 65 ° C and a pulling clamp speed of 10 cm / minute measured.

The tear-off force in the case of the 12 'and 13' samples produced is less than 10 g / cm.

Example 6 1) Solution of 30 g of the polymer prepared according to Example 1 (1) in 70 g of styrene 20 parts by weight 2) solution of 70 g of a conventionally prepared unsaturated polyester (maleic acid / o-phthalic acid in a molar ratio of 70:30 and Propylene glycol) in 30 g of styrene 40 parts by weight 3) Fine calcium carbonate 90 Parts by weight 4) Benzoyl peroxide 0.5 parts by weight 5) Stearic acid 1.5 parts by weight Die The above ingredients 1 to 5 are mixed. The mixture is in a Mold filled and then pressed at 130 ° C under a pressure of 100 kg / cm², wherein a molded part with a smooth surface is obtained.

The shrinkage during pressing is 0.18%.

In a comparative experiment, components 2 to 5 (without Using component 1 and using GO parts by weight of the component 2) mixed. The mixture is pressed in the manner described above.

The product obtained in this way is cracked on the surface. The shrinkage when pressing is 2.31% / The shrinkage when pressing is as follows Equation calculated: (size of) - (size of) From molding shrinkage = x100 when pressing,% (size of the mold)

Claims (8)

P a t e n t a n s p r ü c h e 1) Copolyester, containing a) terephthalic acid, b) isophthalic acid, c) an aliphatic dicarboxylic acid of the formula HOOC- (CH2) n-COOH, in which n is an integer from 4 to 7, d) ethylene glycol and e) neopentyl glycol, in the following molar ratios: 50/50 # [(a) + (b)] / (c) # 75/25 30/70 # (a) / (b) # 70/30 40/60 # (d) / (e) # 80/20. 2) copolyester according to claim 1, characterized in that the components are in the following molar ratios: 55/45 # [(a) + (b)] / (c) # 65/35 30/70 # (a) / (b) # 70/30 40/60 ft (d) / (e) M 80/20. 3) copolyester according to claim 1 and 2, characterized in that they as aliphatic dicarboxylic acid (c) adipic acid, pimelic acid, suberic acid and / or Contain azelaic acid. 4) copolyester according to claim 1 to 3, characterized in that they contain adipic acid as aliphatic dicarboxylic acid (c). 5) copolyester containing a) terephthalic acid, b) isophthalic acid, c) Adipic acid, d) ethylene glycol and e) neopentyl glycol, the molar ratio of Components (a) / (b) / (c) 25-35 / 25-35 / 35-45 and the molar ratio of the components (d) / (e) is 50-60 / 40-50. # Process for the production of copolyesters according to claims 1 to 4, characterized in that components (a) to (e) are used in such quantitative proportions copolymerized that the five components in the copolyester in the following molar ratios available: 50/50 # [(a) + (b)] / (c) # 75/25 30/70 # (a) / (b) # 70/30 40/60 # (d) / (e) # 80/20 7) Process for the production of copolyesters according to claim = characterized that the five components are copolymerized in such a proportion, that the molar ratio of components (a) / (b) / (c) in the copolyester is 25-35 / 25-35 / 35-45 and the molar ratio of components (a) / (b) in copolyester is 50-60 / 40-50. 8) Process according to claim 6, characterized in that a) dimethyl terephthalate, b) dimethyl isophthalate, c) adipic acid, d) ethylene glycol and e) neopentyl glycol in copolymerized in such a quantitative ratio that in the copolyester the molar ratio of components (a) / (b) / (c) 25-35 / 25-35 / 35-45 and the molar ratio of the components (d) / (e) is 50-60 / 40-50.