JPS5846206B2 - polyester resin composition - Google Patents

Description

Detailed Description of the Invention The present invention provides a bulk molding compound (hereinafter abbreviated as BMC) or a sheet molding compound (hereinafter referred to as SMC).
Reducing curing shrinkage during compression molding, injection molding, and transfer molding under heating and pressure conditions that are normally carried out to obtain a useful shape and appearance with high commercial value; This relates to improvements in paint properties and paintability.

Conventional SMC or BMC using polyester resin has large polymerization shrinkage during curing, the surface of molded parts is rough and undulating, and fibers are noticeable.
Additionally, this part was distorted and had poor dimensional accuracy, and had defects such as dents and cracks on the backs of ribs and bosses.

By blending various additives and various thermoplastic resins, these defects such as surface smoothness, dimensional accuracy, and dents on the back of ribs and bosses caused by polymerization shrinkage during curing have been significantly improved. By blending various additives and various thermoplastic resins, and in order to maximize their low shrinkage imparting effect, the α/β-ethylene type that occupies the α/β-ethylenically unsaturated polyester. High mole fractions of unsaturated acids reduce mechanical strength, leading to chipping and cracking of molded products when handled, and shortening their lifespan when put into practical use.

Further, conventional thermoplastic resins used for the purpose of providing low shrinkage properties often have few polar groups, which has been a factor in reducing paintability.

An object of the present invention is to provide a polyester resin composition that solves various conventional technical drawbacks and provides molded products with excellent surface smoothness, dimensional accuracy, mechanical strength, and paintability.

The present invention provides (1) α/β-ethylenically unsaturated polyester 30
~70 parts by weight (2) Polymerizable monomer 20 to 60 parts by weight (3) i) ε-caprolactone and glycol and/or
or reaction product with polyhydric alcohol, 11) saturated polyester or 111) one or more α/β-ethylenically unsaturated bonds in the molecular chain obtained by reacting polycaprolactone with dialkyl fumarate diisocyanate, ester Molecular weight 3,000~ with bond and urethane bond
The present invention relates to a polyester resin composition comprising 3 to 20 parts by weight of 100,000 polymers.

The α/β-ethylenically unsaturated polyester used in the present invention is composed of an α/β-ethylenically unsaturated dibasic acid and, if necessary, an aliphatic saturated dibasic acid, an aromatic dibasic acid, or an alicyclic dibasic acid. It is obtained by performing a polycondensation reaction with a polyhydric alcohol using as an acid component.

Examples of α/β-unsaturated dibasic acids include maleic acid,
Maleic anhydride, fumaric acid, itaconic acid, citraconic acid, etc. are used as necessary, adipic acid, cepacic acid, etc. are used as aliphatic saturated dibasic acids, and aromatic dibasic acids are used as necessary. is orthophthalic acid,
Phthalic anhydride, isophthalic acid, terephthalic acid, etc. are used, and if necessary, as the alicyclic dibasic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, etc. are used.

Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene gellicol, dipropylene glycol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, isopentyl glycol, and hydrogenated bisphenol A.

Examples include 1,4-butanediol, 2,2bis(para(hydroxy-n-7'ropoxy)phenyl)propane, and the like.

Examples of polyhydric alcohols include trimethylolpropane, chrycerin, and pentaerythritol.

Polymer monomers include styrene, chlorstyrene, α-
Methylstyrene, vinyl acetate, methyl methacrylate,
Diaryl phthalate, tertiary butyl styrene, etc. are used.

One or more α/β in the molecular chain used in the present invention
- A polymer having a molecular weight of 3,000 to 100,000 and having an ethylenically unsaturated bond, an ester bond, and a urethane bond is produced, for example, as follows.

(1) ε-caprolactone and ethylene glycol,
A dialkyl fumarate diisocyanate is reacted with a reaction product of a glycol such as diethylene glycol, flopylene glycol, polyethylene glycol, 1,3-butanediol, and/or a polyhydric alcohol such as trimethylolpropane, chrycerin, and pentaerythritol.

[) Adipic acid, orthophthalic acid, terephthalic acid,
A dialkyl fumarate diisocyanate is reacted with a saturated polyester, which is a condensation product of a saturated dicarboxylic acid such as isophthalic acid and/or its acid anhydride, and a glycol and/or polyhydric alcohol.

(IIO polycaprolactone is reacted with dialkyl fumarate diisocyanate.

Examples of the dialkyl fumarate diisocyanate include diethyl fumarate diisocyanate and dipropyl fumarate diisocyanate.

In the present invention, the molecular weight is 3, containing one or more α/β-unsaturated bonds, ester bonds, and urethane bonds in the molecular chain.
Although the mechanism of action of the 000 to 100,000 polymer (hereinafter abbreviated as unsaturated polyester urethane) on improving performance such as mechanical properties and paintability, which is the objective of the present invention, is not clear, the following is generally known. Conceivable.

Conventionally, thermoplastic resins that have been used to provide low shrinkage properties are often incompatible with unsaturated polyester resins, forming an independent phase in the cured polyester resin and existing dispersed therein. There are no chemical bonds at the interface of the thermoplastic resin phase.

Therefore, when mechanical strain is applied, stress is concentrated on the independent phase of the thermoplastic resin, and it is thought that the mechanical strength becomes lower than that of the polyester resin alone.

However, the unsaturated polyester urethane used in the present invention has a molecular skeleton similar to that of the main component α/β-ethylenically unsaturated polyester, so it has high compatibility and is difficult to form an independent phase. It is thought that due to the presence of bonds, chemical bonds are formed by the polymerizable monomers at the interface between the polyester resin phase and the unsaturated polyester urethane phase during molding, making it possible to obtain mechanically high-strength molded products.

Furthermore, since ester bonds and urethane bonds are present in unsaturated polyester urethane, it is thought that when a molded article is coated, the adhesion with the coating film is improved.

The polyester resin composition of the present invention contains 20 to 60 parts by weight of a polymerizable monomer and 3 to 20 parts by weight of unsaturated polyester urethane based on 30 to 70 parts by weight of α/β-ethylenically unsaturated polyester.

If the polymerizable monomer is less than 20 parts by weight, it is SMC.

It impairs kneading properties during BMC processing, wetting with reinforcing agents and fillers, and reduces the fluidity of SMC and BMC.
If it exceeds 0 parts by weight, the mechanical strength of the molded product will be significantly reduced, and painted molded products will be more likely to develop blisters during coating film formation or during use.

Furthermore, if the amount of unsaturated polyester urethane is less than 3 parts by weight, a good low shrinkage effect cannot be obtained, and if it exceeds 20 parts by weight, it cannot be put to practical use due to a decrease in mechanical strength or lack of rigidity.

If the molecular weight of the unsaturated polyester urethane is less than 3.000, there will be no shrinkage reduction effect, while if it exceeds 100.000, the processability and moldability of SMC or BMC will deteriorate and it cannot be put to practical use.

The polyester resin composition of the present invention can be used in SMC or BMC.
Ingredients used as necessary when processing, etc.
These include fillers, extenders, reinforcing fibers, organic peroxides, polymerization inhibitors, internal mold release agents, thickeners with a thickening ratio of 14°, colorants, etc.

Furthermore, polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl acetate, ABS,
Thermoplastic resins such as polyvinyl chloride, ethylene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, polyethylene terephthalate, polyacrylonitrile, polystyrene, polymethyl methacrylate, etc. may be added.

By using the polyester resin composition of the present invention, the selection range of materials such as components used according to the above-mentioned needs is widened.

These can be those widely used by those skilled in the art,
The selection is not limited.

Depending on the application, it is not necessary to use all of the above ingredients.
A detailed description of the present invention will be given below.

Parts are by weight.

Example 1 (1) 7 moles of maleic anhydride, 3 moles of isophthalic acid, 5 moles of 1.3-j tanediol, and 6 moles of propylene gellicol were esterified using a known method to obtain α with an acid value of 25.
- 65 parts of β-ethylenically unsaturated polyester is dissolved in 35 parts of styrene monomer in which 0.01 part of hydroquinone is dissolved to obtain an unsaturated polyester resin (UP-1).

(2) After reacting 5.5 moles of ε-caprolactone and 2.8 moles of diethylene glycol using 0.003% by weight of dibutyltin silaurylate as a catalyst for 180°010 hours, 326 g of the reaction product and diethyl fumarate diisocyanate were obtained. 212.19 and rosebenzoquinone 0.
A 30% by weight styrene solution composition (UPU-1) of unsaturated polyester urethane was obtained by reacting for 1 hour at IOOO° C. in a styrene solution containing 0.04% by weight (concentration: 30% by weight).

(3) 3 moles of terephthalic acid, 3 moles of isophthalic acid, 4 moles of ethylene glycol, and 4 moles of neopentyl glycol
mol and were esterified at 210°C using 0.01% by weight of tetrabutyl titanate as a catalyst until the acid value reached 20, and then esterification was continued under reduced pressure of 0.1 mmHg to reach an acid value of 4. A saturated polyester was obtained.

This product was made up to 30% by weight based on styrene in which 0.05 part of rosebenzoquinone was dissolved, and 1.8 mol of diethyl fumarate diisocyanate and dibutyltin silaurylate were added at 0.003% by weight based on the total amount of the above components. The mixtures were mixed and reacted at 60°C for 5 hours to obtain a 30% by weight styrene solution of unsaturated polyester urethane (UPU-2).

(4) 6 moles of polycaprolactone (molecular weight 700) and 1.6 moles of diethyl fumarate diisocyanate were adjusted to 30% by weight based on styrene in which 0.04% by weight of rosebenzoquinone was dissolved, and dibutyltin silaurylate was added to the above components. Contains 0.003% by weight based on the total amount at 80℃
for 6 hours to form an unsaturated polyester urethane (UPU).
-3) was obtained.

(5) (1) , (2) , (3) and (4)
Polyester resin compositions (1), (II), and (I[D) were prepared using the ingredients prepared in Table 1 as shown in Table 1.

Table 1 Unit: parts The prepared resin composition was SM
C was produced.

Polyester resin composition (1), (■) or (III) l 0 parts Rosebenzoquinone 0.01 Tertiary butyl peroxybenzoate 1.0a Zinc stearate 3.0 Calcium carbonate 150 Magnesium oxide 10 These components ( , A) were mixed well so that 30 parts of chopped strand glass cut into 1 inch length was added to 70 parts of mixture (A), and this SMC was heated at 48°C at 40°C.
Thickening was completed under the condition of time to obtain SMC-1, 2 and 3.

Comparative Example (1) 65 parts of α/β-ethylenically unsaturated polyester with an acid value of 25 obtained by esterifying 10 moles of maleic anhydride and 11.1 moles of propylene glycol by a known method, and 1 part of hydroquino, Dissolved styrene monomer 35
% to obtain an unsaturated polyester resin (UP-2).

(2) Thermoplastic polymerized by a known method from 85 parts of methyl methacrylate, 12.5 parts of ethyl methacrylate, and 2.5 parts of acrylic acid to have a molecular weight in the range of 50,000 to 100,000. The resin was dissolved in styrene monomer to a solid content of 30% (TP-1).

A styrene solution of polystyrene (TP-2) was obtained by repeating the same method as TP-1 except that it was prepared from polystyrene having a molecular weight of Zoo, 000 to 200,000.

Polyester resin compositions (IV), (V) and (VD) were prepared using UP-1, UP-2, TP-1, TP-2 and finely powdered polyethylene according to the formulations shown in Table 2.

SMC was prepared in the same manner except that these compositions (IV), (V) and (Vl) were replaced with polyester resin compositions (1), (■) or (IID) in component (4) shown in the examples. was produced to obtain SMC-4, 5 and 6.

Using these SMC-1 to 6 shown in Examples and Comparative Examples, a flat plate of 30 CrIL square and 3 wall thickness, and a vertical 30 cm
rrL1 width 20CrIl, depth 5CIrL, wall thickness 3
A box-shaped molded product (width 3mm, depth 30mm ribs and diameter 20mm post-each with slope position 0) was placed at a mold temperature of 1.
40-145℃, molding pressure 10MPa (100kg/c
rrL2) was molded using a matte die molding method under conditions of a molding time of 3 minutes.

flat plate and box type with rib boss, molding shrinkage rate, surface roughness,
Table 3 shows the results of testing surface gloss, mechanical strength, and paintability.
Shown below.

The SMC molded product of the present invention using a resin composition containing unsaturated polyester urethane has good mold shrinkage and surface roughness, and also has high mechanical strength and toughness, good paintability, and a coating film. It has particularly good adhesion.

■) After baking, industrial materials, l 4(a) 172 (196
6) Tested according to the method described.

2) After processing for 72 hours at 50°C and 98% dew condensation and returning to normal conditions, the test was performed using the method described in 1) above.

The polyester resin composition of the present invention can be used in SMC or BMC.
Molded products obtained using Nato's molding materials have a molding shrinkage rate of 0.10% or less, no cracks, high dimensional accuracy, no distortion, and no sink marks on the back of ribs or bosses. It exhibits excellent physical properties such as no ”, excellent surface smoothness, and high gloss.

The molded product has high mechanical strength and toughness, and is less likely to crack or break during handling or use.

Furthermore, when painted, coating defects such as blisters and pinholes are less likely to occur during coating film formation, and the adhesion between the coating film and the substrate (molded product) is improved.

Claims (1)

[Claims] 1(1) α, β-ethylenically unsaturated polyester 30-
70 parts by weight (2) 20 to 60 parts by weight of polymerizable monomer (3) i) Reaction product of ε-caprolactone and glycol and/or polyhydric alcohol 11) Saturated polyester or 111) Polycaprolactone and dialkyl fumarate 3 to 20 parts by weight of a polymer having a molecular weight of 3,000 to 100,000 and having one or more α/β-ethylenically unsaturated bonds, ester bonds, and urethane bonds in the molecular chain obtained by reacting with diisocyanate. A polyester resin composition comprising: