GB2039928A

GB2039928A - Polyester resin composition

Info

Publication number: GB2039928A
Application number: GB8001541A
Authority: GB
Original assignee: Kao Corp; Kao Soap Co Ltd
Current assignee: Kao Corp
Priority date: 1979-01-23
Filing date: 1980-01-17
Publication date: 1980-08-20
Also published as: DE3000539A1; GB2039928B; FR2447385B1; FR2447385A1; JPS5599916A; JPS592447B2

Abstract

A polyester resin is produced by a reaction of: (A) a dicarboxylic acid and (B) a polyol comprising an etherified diphenol of the formula (I): <IMAGE> in which R is alkylene having 2 or 3 carbon atoms; and x and y are each a positive integer of which the average sum is from 2 to 7, and (C) from 0.05 to 10 mol %, based on the polyol (B), of a compound having (i) one or two phenolic -OH groups and (ii) an alcoholic -OH group or a -COOH group. This polyester does not cake or block.

Description

SPECIFICATION Polyester resin composition The present invention relates to a novel polyester resin in which caking or blocking is hardly caused.

It is well-known that a polyester resin can be obtained from an etherified diphenol and a dicarboxylic acid and further improved by the use of a polyol having three or more functional groups, see United States Patents Nos. 3,787,526 and 3,681,106.

Those polyester resins alone or in combination with suitable amounts of additives, pigments, etc., are used in fine powder form as binders for mineral fibers and electrophotographs. However, in many cases, undesirable caking or blocking is caused during use or storage.

In the use of polyester resin powders as binders for glass fibers, carbon fibers and electrophotographs, there are optimum softening points. If the softening point is too high, there is a possibility of gelation during production and, in addition, energy is wasted and, during use as a binder in electrophotography, the paper becomes denatured. On the other hand, if the softening point is lowered, the melting point is inevitably lowered and blocking or caking is caused.

If the softening point is raised, the melting point is also raised a little but it is not always elevated to a point in the preferred temperature range but rather undesirable phenomena such as described above are invited.

The softening point is determined by the ring-and-ball test according to Japanese Industrial Standard K-2531. The softening point is an important factor in the adhesion of glass fibers and toner fixing in electro-photography.

The melting point is determined by D.S.C. (differential scanning calorimeter). If the melting point is too low, caking or blocking is apt to be caused which seriously affects the storage stability of the resin.

Therefore, for overcoming the above described defects, it is required to elevate the melting point by such a method that properties such a adhesion, thermal stability and solubility in'styrene do not deteriorate in the production of glass fibers, or adhesion, picture quality, electrical propertiess and clarity do not deteriorate in electrophotography.

Though there has been proposed a method in which an additive such as a caking-preventing agent is added, such a.method-often causes reduction in capacity and therefore is not satisfactury.

The present invention provides novel polyester resins free of these disadvantages.

The present invention relates to a polyester resin composition produced by the reaction.of: (A) a dicarboxylic acid or anhydride and (B) a polyol comprising an etherified diphenol of the formula (I):

in which is alkylene having 2 or 3 carbon atoms; and x andy are each a positive integer of which the average sum is from 2 to 7, and (C) from 0.05 to 10 mol %, based on the polyol (B), of a compound having one or two phenolic -OH groups and an aliphatic or alicyclic -OH group or a -COOH group.

Some examples of compound (C) are diphenolic acid, p-hydroxybenzoic acid, 2, 4-dihydroxybenzoic acid, p-hydroxyphenylacetic acid, p-hydroxyphenylacetic acid, p-hydroxybenzyl alcohol, phenolphthalin, hyd- roxypropylene-2, 2-bis (4-hydroxyphenyl) propane, hydroxyethylene-p, p' -bisphenol, hydroxypropylene bis(4-hydroxyphenyl) thioether and hydroxybutylene-bis (4-hydroxyphenyl)ketone. Particularly preferred compounds are hydroxypropylene-2,2-bis(4-hydroxyphenyl)propane, diphenolic acid (i.e. 4,4-bis(phydroxyphenyl)-n-valeric acid) and 2,4-dihydroxy-benzoic acid.

The compound (C) is used desirably in an amount of 0.05-10 molar % based on the polyol components The carboxylic acids used in the present invention are preferably dicarboxylic acids of general formula (ill):

wherein A represents any of CH2 An, - CH = CH -, phenylene or cyclohexylene and n represents an integer from 1 to 4, where anhydrides are used, these are preferably derived from such acids. These carboxylic acids include, for example, fumaric acid, maleic acid, succinic acid, malonic acid, cyclohexane dicarboxy ic acid, glutaric acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid anhydride and phthalic acid anhydride.

In the polyol (B) the sum ofx andy is preferably 2 or 3. Preferred examples of the polyol (B) are polyoxyethylene (3)-2, 2-bis(4-hydroxyphenyl)propa ne, polyoxypropylene(3.2)-2,2-bix(4-hydroxyphenyl) propane, polyoxypropylene(2.2)-2-bis(4-hydroxyphenyl)propane and polyoxeythylene(2.5)-2,2bis(hydroxyphenyl)propane.

The polyol (B) can be used alone, or accompanied by another polvol in an amount of up to 20 mol % based on the polyol (B). The additional polyol includes ethylene glycol, propyle glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1, 3-dihydroxybutane, 1,4-dihydroxypentane and hydrogenated bisphenol A. Among them, particularly preferred compounds are ethylene glycol, propylene glycol, neopentyl glycol and hydrogenated bisphenol A.

Polyols having 3-6 hydroxyl groups may be used as the additional one. For example, glycerol, trimethylolpropane, sorbitol, pentaerythritol, xylitol, 1,2,3-butanetriol and 1 ,2,5,6-hexanetraol.

The reaction of the dicarboxylic acids with specific compounds of the above general formula (I) and the compound (C) is carried out preferably at about 200"C in an inert atmosphere. Catalysts and promotors generally used in the production of polyester resins may be used in the present invention for increasing reaction velocity. Where unsaturated dicarboxylic acids are used, it is desirable to add a small amount of a polymerization inhibitor such as hydroquinone or pyrogallol. The esterification catalyst or the like is desirably incorporated in a non-excess amount so as to minimize contamination of the polyester products.

The reaction is carried out under atmospheric pressure. The reaction may be carried out also under reduced pressure in order to accelerate it.

The ratio of dicarboxylic acid to polyol is determined so that the ratio of the number of hydroxyl groups in the polyol to the number of carboxyl groups in the dicarboxylic acid is from 0.8 to 1.3, preferably 0.9 to 1.2.

The present invention will be illustrated in more detail by way of the following examples. In the examples, caking and blocking are tested for by the following method: 100 Grams of a powder of a given particle size are allowed to stand at 30-40"C under a relative humidity of 30-100%, if necessary under a load of about 1 kg, for one week. Then, the powder is dropped onto a 40 mesh sieve from a height of 1 m and the solid remaining on the sieve is weighed to obtain the caking index.

Example 1 175 Grams (1,507 moles) of fumaric acid, 528 g (1.50 moles) of polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)-propane, 24 g (0.074 mole) of phenolphthalin and 0.3 g of hydroquinone were charged in a 1-liter four- necked round flask provided with a thermometer, stirring rod, dehydrating tube having flowing-down type condenser and nitrogen-introducing tube. The flask was supported by an electric heating jacket.

Nitrogen gas was introduced to provide an inert atmosphere in the reaction vessel. Then, the flask was heated to fuse the reagents.

The reaction was carried out at a temperature maintained at 210"C for 5 hours while nitrogen gas was introduced at a rate of 5-10 graduations on a flow meter (type KG-2; a product of Kusano Kagaku Kiki seisaku-sho) (100-150 me/min). Thereafter, pressure was gradually reduced and the reaction was continued under about 100 mm/Hg for 100 minutes until a softening point of 99"C was attained. The resulting resin had an acid value of 20 mgKOH/g and a melting point of 61.5"C. The molecular weight of the product measured according to the VPO method was 2130.

The resulting resin was cooled and pulverized. 0.05 Gram of the powder which passed through a 200 mesh sieve was sprinkled over an end (30 mm2) of a glass cloth (40 mm width x 150 mm length) and then another glass cloth of the same size was laid thereon. The cloths were pressed together under a load of 1.2 kg at 185"C for three minutes to obtain a united test piece. The adhesive strength of the test piece measured was 1.4 kg/cm. The measurement was effected with Shimazu autograph at a crosshead speed of 50 mmlmin and a chart speed of 200 mm/min.

0.025 Gram of the powder of the same particle size as above was sprinkled over an end (25 x 30 mm) of a glass cloth (25 mm width x 150 mm length) and then another glass cloth of the same size was laid thereon.

The cloths were pressed together under a load of 1.2 kg at 185"C for three minutes to obtain a united test piece. The test piece was provided with a weight of 20 g and suspended in styrene monomer two measure its solubility in styrene. The result was 4 minutes and 10 seconds.

Example 2 179.5 Grams (1.55 moles) of fumaric acid, 528 g (1.50 moles) of polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane, 9.3 g (0.075 mole) of p-hydroxybenzyl alcohol and 0.3 g of hydroquinone were reacted together at 210"C for 5 hours in the same device as in Example 1. Then, pressure was reduced gradually and the reaction was continued under about 100 mm/Hg for 90 minutes till softening point of 99"C was attained.

The resulting resin had an acid value of 20 mg KOHig and a melting point of 63"C. Molecular weight of the product measured according to VPO method was 2590.

The thus-obtained resin was finely divided to the same particle size as in Example 1. A limited test piece was prepared as described above using glass cloths and the adhesive strength was measured to obtain a value of 1.6 kg/cm. The solubility of the product in styrene was 3 minutes and 14 seconds.

Example 3 204.2 Grams (1.757 moles) of fumaric acid, 616 g (1.75 moles) of polyoxypropylene(2.2)-2,2-bis (4-hydroxyphenyl)propane, 0.5 g (0.0017 mole) of diphenolic acid and 0.34 g of hydroquinone were reacted together at 210"C for 5 hours in the same device as in Example 1. Then, the pressure was reduced gradually and the reaction was continued for about 120 minutes till a softening point of 99"C was attained. The resulting resin had an acid value of 20 mg KOH/g and a melting point of 61.5"C. The molecular weight of the product measured bv the VPO method was 2310.

The resulting resin was finely divided to the same particle size as in Example 1. A united test piece was prepared using glass cloths and the adhesive strength was measured to obtain a value of 1.6 kg/cm. The solubility of the product in styrene was 4 minutes.

Comparative Example 1 209 Grams (1.8 moles) of fumaric acid, 616 g (1.75 moles) of polyoxypropylene(2.2)-2,2-bis(4-hydroxy phenyl)-propane and 0.33 g of hydroquinone were reacted together at 210"C for 5 hours in the same device as in Example 1. Then, the reaction was continued under reduced pressure for 110 minutes till a softening point of 99"C was attained. The resulting resin had an acid value of 21 mg KOH/g and a melting point of only 58"C. The molecular weight of the product measured according to VPO method was 2450.

The thus-obtained resin was finely divided to the same particle size as in Example 1. A united test piece was prepared using glass cloths and the adhesive strength was measured to obtain a value of 1.6 kg/cm.

Solubility of the product in styrene was 3 minutes and 40 seconds.

Example 4 230.7 Grams (1.987 moles) of fumaric acid, 651.2 g (1.85 moles) of polyoxypropylene (2.2)-2,2-bis(4hydroxyphenyl)propane, 26.5 g (0.09 mole) of diphenolic acid and 0.45 g of hydroquinone were reacted together at 21 0"C for 7 hours in the same device as in Example 1. Then, 7.5 (0.08 mole) of glycerol was added thereto and the reaction was carried out for about 2 hours. Thereafter, the pressure was reduced gradually and the reaction was continued for 2 hours until a softening point of 107"C was attained. The resulting resin had an acid value of 23 mg KOH/g and a melting point of 63"C. The molecular weight of the product measured according to VPO method was 2610.

The thus-obtained resin was finely divided to the same particle size as in Example 1. A test piece was prepared using glass cloths and adhesion strength was measured to obtain a value of 1.23 kg/cm. solubility of the product in styrene was 3 minutes and 5 seconds.

Example 5 230.7 Grams (1.987 mole) of fumaric acid, 651.2 g (1.85 moles) of polyoxypropylene (2.2)-2,2-bis(4hydroxyphenyl)propane, 16.3 g (0.057 mole) of oxypropylene-2, 2-bis(4-hydroxyphenyl)propane and 0.45 g of hydroquinone were reacted together at 210"C for 7 hours in the same device as in Example 1. Then 7.5 g (0.08 mole) of glycerol were added thereto and the reaction was carried out for about 2 hours. Thereafter, the pressure was reduced gradually and the reaction was continued under 100 mmHg till a softening point of 107"C was attained. The resulting resin had an acid value of 24 mg KOH/g and a melting point og 61.5"C. The molecular weight of the product measured according to VPO method was 2650.

Comparative Example 2 230.7 Grams (1.987) of fumaric acid, 678.5 (1.982 moles) of polyoxypropylene(2.2)-2,2-bis(4hydroxyphenyl )propane and 0.45 g of hydroquinone were reacted together for 7 hours in the same manner as in Example 1. Then, 7.5 g (0.08) of glycerol was added thereto and the reaction was effected for about 2 hours till a softening point of 1 07"C was attained. The resulting resin had an acid value of 24 mg KOH/g and a melting point of only 59"C. The molecular weight of the product measured according to VPO method was 3000.

The thus obtained resin was finely divided to the same particle size as in Example 1. A test piece was prepared using glass cloths and the adhesion strength was measured to obtain a value of 1.17 kg/cm. The solubility of the product in styrene was 4 minutes.

Example 6 473.9 Grams (3.2 moles) of phthalic anhydride, 591.4 g (1.68 moles) of polyoxypropylene(2.2)-2.2-bis (4-hydroxyphenyl)propane, 104.4 g (1.68 moles) of ethylene glycol and 24.7 g (0.16 mole) of 2,4 dihydroxybenzoic acid were reacted together at 21 OOC for 8 hours in the same manner as in Example 1. Then, the pressure was reduced gradually and the reaction was continued under a pressure of 100 mmHg for about 7 hours till a softening point of 90"C was attained. The resulting resin had an acid value of 2 mg KOH/g and a melting point of 48 C. The molecular weight of the product measured by VPO method was 2390.

As compared with Comparative Example 3, the melting point of the product was higher by 3"C, though the softening point was the same.

Comparative Example 3 485.8 Grams (3.28 moles) of phthalic anhydride, 591.4 g (1.68) of polyoxypropylene(2.2)-2,2-bis (4-hydroxyphenyl)propane and 104.4 g (1.68 moles) of ethylene glycol were reacted together at 2100C for 8 hours in the same manner as in Example 1. Then, the pressure was reduced gradually and the reaction was continued under a pressure of 100 mmHg for about 7 hours till a softening point of 90"C was attained. The resulting resin had an acid value of 2 mg KOH/g and a melting point of only 45"C. The molecular weight of the product, as measured by the VPO method, was 2530.

Example 7 191 Grams (1.616 moles) of succinic acid, 184.7 g (0.728 mole) of hydrogenated bisphenol A, 256.7 g (0.728 mole) of polyoxypropylene(2.2)-2,2-bis(4-hydroxy-phenyl)-propane and 9.9 g (0.08 mole) of p-hydroxybenzyl alcohol were reacted together at 210"C for 6 hours in the same manner as in Example 1. Then, 8.6 g (0.064 mole) of trimethylolpropane were added and the reaction was carried out for about 1.5 hours. The reaction was further continued under reduced pressure for about 1.5 hours till a softening point of 92"C was attained.

The resulting resin had an acid value of 25 mg KOH/g and a melting point of 51"C. The molecular weight of the product as measured by the VPO method was 2150.

Comparative Example 4 194.6 Grams (1.648 moles) of succinic acid, 194.8 g (0.768 mole ) of hydrogenated bisphenol A and 270.3 g (0.768 mole) of polyoxypropylene(2.2)-2.2-bis (4-hydroxyphenyl)-propane were reacted together at 210"C for 6 hours in the same manner as in Example 1. Then, 8.6 Grams (-.728 mole) of trimethylol-propane were added thereto and the reaction was carried out for about 1.5 hours. The reaction was further continued under reduced pressure for about 1.5 hours till a softening point of 92"C was attained. The resulting resin had an acid value of 25 mg KOH/g and a melting point of only 49 C. The molecular weight of the product as measured by the VPO method was 2190.

Example 8 90 Parts of the resin obtained in Example 1 were kneaded by fusion with 10 parts of carbon black in hot rollers. The mixture was cooled, pulverized and a powder which passed through a 150 mesh sieve but did not pass through a 200 mesh sieve was collected. The powder was dried at ambient temperature for two days. 40 Grams of the powder were charged in a 50 mf beaker and allowed to stand at 40"C under a relative humidity of 100% for two days. The caking index was found to be 30 (namely, 30 wt. % of the powder was caked). 90 parts of the resin were kneaded with 10 parts of carbon black by fusion.The mixture was cooled, pulverized and further finely divided with a jet pulverizer to obtain a toner of 5-20 u the toner was used for development according to the cascade method or magnetic brush method. In both developing methods, clear images were obtained without causing fogging or trailing in the visualization of the negative electrostatic latent images.

Comparative Example 5 90 Parts of the resin obtained in comparative Example 1 were kneaded by fusion with 10 parts of carbon black using hot rollers. The mixture was cooled and pulverized and a powder which passed through a 150 mesh sieve but did not pass through a 200 mesh sieve was collected and its caking index was measured in the same manner as in Example 8 to obtain a value of 75 (namely, 75 weight % thereof was caked).

Example 9 90 parts of the resin obtained in Example 5 were kneaded by fusion with 10 parts of carbon black using hot rollers. The mixture was cooled and pulverized and a powder which passed through a 150 mesh sieve but did not pass through a 200 mesh sieve was collected and the caking index thereof was measured in the same manner as in Example 8 to obtain a value of 5 (namely, 5 wt. % thereof was caked).

The caking index of the product after it had been allowed to stand under a load of 920 g for one week was 10. 90 parts of the resin were kneaded by fusion with 10 parts of carbon black using hot rollers. The mixture was cooled, pulverized and further finely divided with a jet pulverizer to obtain a toner of 5-20 p The toner was used for development by the cascade method or magnetic brush method. In both methods, clear images were obtained without causing fogging or trailing in the visualization of the negative electrostatic latent images.

Comparative Example 6 90 Parts of the resin obtained in Comparative Example 2 were kneaded by fusion with 10 parts of carbon black using hot rollers. The mixture was cooled, pulverized and a powder which passed through a 150 mesh sieve but did not pass through a 200 mesh sieve was collected and the caking index thereof was measured in the same manner as in Example 8 to obtain a value of 38 (namely, 38 wt. % of the powder was caked).

The caking index of the product after it had been allowed to stand under a load of 920 g for one week was 45.

Claims

1. A polyester resin composition produced by a reaction of: (A) a dicarboxylic acid or anhydride and (B) a polyol comprising an etherified diphenol oftheformula (I):

in which R is an alkylene having 2 or 3 carbon atoms: and x andy are each a positive integer the average sum of which is from 2 to 7, and (C) from 0.05 to 10 mol %, based on the polyol (B), of a compound having one or two phenolic -OH groups and an aliphatic or alicyclic -OH group or a -COH group.

2. A polyester resin composition as claimed in Claim 1 in which the proportion of -OH groups in the polyol to carboxyl groups in the dicarboxylic acid is from 0.8 to 1.3.

3. A polyester resin composition as claimed in Claim 1 or Claim 2 in which the polyol (B) contains up to 20 mol % of another diol based on the polyol (B) of formula (I).

4. A polyester resin composition as claimed in any preceding claim in which the dicarboxylic acid or anhydride is or is derived from an acid respectively of the formula (Il):

wherein A istCH2+n, - CH = CH -, a phenylene group or a cyclohexylene group and n is an integer from one to four, or an anhydride thereof.

5. A polyester resin composition as claimed in any preceding claim in which the compound (C) is diphenolic acid, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, p-hydroxyphenylacetic acid, phydrobenzyl alcohol, phenolphthalin, hydroxypropylene-2,2-bis(4-hydroxyphenyl) propane, hydroxyethylene-p,p' - bisphenol, hydroxypropylene-bis(4-hydroxyphenyl )thioether or hydroxybutylene-bis(4hydroxyphenyl)Ketone.

6. A polyester resin composition as claimed in any preceding claim in which the polyol (B) is polyoxyethylene (3)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene(3.2)-2,2-bis(4hydroxyphenyl)propane, polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane or polyoxyethylene (2.5) 2, 2-bis(4-hydroxyphenyl)propane.