JPS60248772A - Unsaturated polyester resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition giving a molded article free from warpage and sink and having excellent surface slippery, etc., and suitable for the production of SMC, etc., by compounding a specific unsaturated monomer, an acid group-containing thermoplastic polymer, a saturated polyester and a bivalent metal oxide or hydroxide. CONSTITUTION:The objective composition can be produced by compounding (A) an unsaturated polyester having an average molecular weight of 500-10,000 with (B) an unsaturated monomer copolymerizable with the component A (e.g. styrene), (C) a thermoplastic polymer having carboxyl group at the side chain, (D) a saturated polyester obtained by the reaction of a bivalent carboxyl compound with a bivalent epoxy compound, containing >=2 ester bonds per 1 molecule, and having an average molecular weight of 1,000-100,000 and (E) a bivalent metal oxide or hydroxide (e.g. magnesium oxide). The ratios A/B/C/D are (20-70)/(30-70)/(3-30)/(3-30)(wt%) (the sum of A-D is 100wt%), and the amount of the component E is 0.1-5pts.wt. per 100pts.wt. of the sum of A-D.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides sheet molding compounds (SMC) and bulk molding compounds (BMC) suitable for hot-pressure molding, and molded products with smooth surfaces and no warpage or sink marks. , relates to an unsaturated polyester resin composition with low shrinkage that provides cured molded products with good gloss, such as fiber reinforced plastics (FRP).

Unsaturated polyester is generally cured and molded together with other reinforcing materials, fillers, etc., and is used in a wide range of applications such as bathtubs, septic tanks, and water tank panels. Its shrinkage is large, and therefore molded products made by press molding or injection molding lack surface smoothness.
In addition, defects such as warping (deformation), sink marks (shrinkage), protrusion of glass fibers, and cracks are observed.

In order to solve the above problem, a method has been proposed in which thermoplastic polymers such as polystyrene and polymethyl methacrylate are blended with unsaturated polyester to reduce shrinkage during curing (Japanese Patent Publication No. 46-14541). However, in order to obtain a molded product with a smooth surface and less sink marks and warpage, unsaturated polyester resin compositions containing thermoplastic polymers are used.
When applied to the production of SMC or BMC, the dispersion state of the thermoplastic polymer gradually deteriorates during the thickening process over time, and liquid material oozes out on the surface, resulting in the resulting SMC or BMC having a sticky surface and being difficult to mold. Time handling becomes poor. Furthermore, molded products made using these materials have mottled spots of exuded thermoplastic polymer on the surface, which severely impairs mold releasability, making it impossible to obtain molded products with commercial value. teeth,
There were disadvantages in that pinholes, cissing, surface scratches, etc. occurred.

As a means to solve these problems,
It has been proposed to use acid group-containing thermoplastic polymers (eg, acid group-containing acrylic polymers, acid group-containing vinyl acetate polymers) as shown in Japanese Patent No. 09 as a low-shrinkage agent.

This method provides the possibility of bonding with the terminal carboxyl group of unsaturated polyester via a metal oxide by incorporating acid groups into the thermoplastic polymer, thereby preventing separation and precipitation of the thermoplastic polymer. .

However, unsaturated polyester resin compositions using acid group-containing thermoplastic polymers such as acid group-containing acrylic polymers and vinyl acetate polymers as low shrinkage agents,
When applied to the production of MC and BMC, the general plate thickness is 3~
With the 10-layer method, molded products with smooth surfaces and less deformation such as sink marks and warpage can be obtained. SMC-? BMC
At present, its application to automobile parts is limited.

The inventors of the present invention have conducted various studies in view of the above situation, and as a result,
When an acid group-containing thermoplastic polymer and a saturated polyester are used together as a low-shrinkage agent, warpage (deformation) and sink marks (shrinkage) are extremely small, and surface smoothness and paintability are improved even in molded products with a plate thickness of less than 3 mm. It was discovered that an unsaturated polyester resin composition having good properties and suitable for manufacturing SMC and BMC can be obtained, and the present invention was completed.

That is, the present invention provides (a) an unsaturated polyester, (b) an unsaturated monomer copolymerizable with the unsaturated polyester, (C)
A thermotransferable polymer having a carboxyl group in the side chain, (d
The present invention provides an unsaturated polyester resin composition containing (e) a saturated polyester and (e) an oxide or hydroxide of a divalent metal.

The unsaturated polyester (a), which is the first component for providing the resin composition according to the present invention, is obtained by reacting an unsaturated dihydric carboxylic acid or its anhydride with a dihydric alcohol, The production method is not limited to the condensation reaction, but can be easily produced by methods known in the art. The average molecular weight of such unsaturated polyester is usually 500 to 10,000, preferably 1,000 to 4,000, and the acid value is usually 5 to 1.
00, preferably 10-60.

Various unsaturated dihydric carboxylic acids are used here, and typical examples include maleic acid, fumaric acid, citraconic acid, and itaconic acid. In addition, a part of the unsaturated divalent carboxylic acid or its anhydride may be replaced with a saturated divalent carboxylic acid or its anhydride, unless there is a problem. Such saturated divalent carboxylic acids include, for example, succinic acid, adipic acid, cepatic acid, phthalic acid, inphthalic acid, terephthalic acid,
Examples include tetrachlorophthalic anhydride, tetrabromophthalic anhydride, het acid, and the like.

Examples of dihydric alcohols include ethylene glycol,
Diethylene glycol, polyethylene glycol, furopylene gelicol, 1,6-propanediol, 1,2
-Propanediol, diethylene glycol, 1,3-
Examples include butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, hydrogenated bisphenol, and the like. Of course, each of the dihydric carboxylic acids and dihydric alcohols may be used alone or in combination of two or more thereof.

An unsaturated monomer (
Examples of b) include styrene compounds such as styrene, vinyltoluene, α-methylstyrene, and chlorostyrene; acrylic compounds such as methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, trimethylolpropane triacrylate, and esters thereof; and vinyl monomers or vinyl oligomers that can be crosslinked with unsaturated polyesters such as allyl compounds such as triallyl cyanurate and diallyl phthalate, and are used alone or in combination, but styrene is generally used. .

A thermoplastic polymer having a carboxyl group in its side chain, which is the third component for providing the resin composition according to the present invention (
Examples of monomers constituting Q include styrene,
Examples include vinyltoluene, chlorostyrene, acrylic esters, methacrylic esters, vinyl chloride, vinylidene chloride, acrylonitrile, vinyl acetate, vinyl bromide, vinyl propionate, and ethylene. Of course, they can also be used together. Examples of unsaturated carboxylic acids that are combined with the above monomers to introduce carboxyl groups into the side chains of this polymer include:
Acrylic acid, methacrylic acid, crotonic acid, itaconic acid,
Examples include fumaric acid, maleic acid, fumaric acid monoesters, and maleic acid monoesters. Further, the blending ratio of the monomer and the unsaturated carboxylic acid can be arbitrarily changed depending on the use.

The saturated polyester (d), which is the fourth component for providing the resin composition according to the present invention, has two or more ester bonds per molecule, and the average molecular weight is usually 1.
．． 00 D ~ ioo, ooo, preferably 5,000 ~
4o, ooo.

When the average molecular weight is less than 1.000, a sufficient effect against sink marks (shrinkage) cannot be obtained, and when it exceeds 100,000, a sufficient effect against warp (deformation) cannot be obtained.

Examples of the saturated polyester (d) include those obtained by reacting a known saturated polybasic acid and a polyhydric alcohol in a conventional manner, but unsaturated polyesters (a)
Particularly preferred is a saturated polyester obtained by reacting a divalent carboxy compound and a divalent epoxy compound, since it can be suitably used regardless of the size of the double bond equivalent.

Here, the divalent carboxy compound refers to a compound containing a divalent carboxylic acid and having two carboxyl groups in the molecule. A method in which a terminal hydroxyl-saturated polyester obtained by a condensation reaction between a carboxylic acid and a dihydric alcohol is reacted with an acid anhydride (e.g., phthalic anhydride), a method in which a lactone is ring-opened and polymerized using a dihydric carboxylic acid as an initiator, etc. It is easily obtained.

The dicarboxylic acid used here includes, for example, cono-
Examples of dihydric alcohols include phosphoric acid, adipic acid, sepacic acid, 7-thalic acid, inctaric acid, terephthalic acid, tetrachlorophthalic anhydride, tetrabromo-phthalic anhydride, phthalic anhydride, and succinic anhydride. For example, ethylene glycol, polyethylene glycol, 1.
2-furopanediol, 1,3-propanediol, 1
, 6-butanediol, 1,4-butanediol, 1,
6-hexanediol, neopentyl glycol, hydrogenated bisphenol, 3.5.3-) dichloropropylene oxide, 2-methyl-3,3,3-tric layer, 1-pyrene oxide, dibromoneopentyl glycol, diphenylsulfone dichloro Examples of the lactone include hydride/ether, and examples of the lactone include ξ-caprolactone and r-butyrolactone.

In addition, divalent epoxy compounds include (β-methyl)epichlorohydrin, bisphenol A1, bisphenol F1, bisphenol S1, ethylene glycol,
Propanediol, divalent hydroxy compounds such as divalent hydroxy polyesters having two hydroxyl groups, or adipic acid, sepatic acid, phthalic acid, isophthalic acid, terephthalic acid, divalent hydroxyl compounds having two carboxyl groups, etc.
It is a reaction product with a divalent carboxy compound such as a divalent carboxy polyester, and includes what is generally called an epoxy resin.

Furthermore, a monovalent epoxy compound can be used in combination with this epoxy resin in order to adjust the molecular weight. Examples of the strong monovalent epoxy compound include methyl ester, ethyl ester, or butyl ester of epoxidized stearic acid, Cardura-E (trade name, manufactured by Nigel Co., Ltd.), glycidyl butyl ether, and the like. Of course, each of the above components can be used not only individually but also as a mixture of two or more.

First step to provide a resin composition according to the present invention! il
Examples of the component divalent metal oxide or hydroxide (e) include carboxyl groups of thermoplastic polymers and oxides or hydroxides of alkaline earth metal elements such as unsaturated polyester lucium. Each can be used alone or in combination of two or more.

Usage ratio of unsaturated polyester (a) used in the present invention, unsaturated monomer value copolymerizable with unavoidable phase polyester), thermoplastic polymer having a carboxyl group in the side chain (C), and saturated polyester (d) (a)/(b)/(c)/(d)
is usually 20-70/60-70/3-60/6-60 (
Weight% preferably 25-60/40-6015-20
The range is 15 to 20 (heavy layer), and the proportion of divalent metal oxide or hydroxide (e) is (a) to (d).
) is usually 0.1 to 5 parts by weight per 100 parts by weight of the total amount of
Preferably it is in the range of 0.5 to 3 parts by weight.

In addition, thermoplastic polymers having carboxyl groups in their side chains (
If the ratio of e) is less than 3 layers, the desired effect cannot be obtained sufficiently, and if it exceeds 30 layers, warpage will be large and the surface condition will be poor, which is not preferable. If the proportion of saturated polyester (di) used is less than 6 weight layers, the desired effect cannot be sufficiently obtained, and if it exceeds 30 weight layers, the viscosity increases and workability deteriorates, which is not preferable.

The resin composition of the present invention can be obtained by simply mixing the components (al to (c)) described above by a known method, but in the usual case, first, the unsaturated polyester (a), the thermoplastic polymer (C ), unsaturated monomer (BL) is mixed with each of the saturated polyester (d) to form a solution, and then these solutions are mixed with a divalent metal oxide or hydroxide (e) and other additives. A method of preparing a resin composition is adopted.

The unsaturated polyester resin composition according to the present invention may further contain known compounding agents such as pigments, fillers, reinforcing materials, mold release agents, and flame retardants, if necessary. Preferred examples include fillers such as calcium carbonate, clay, and silica; reinforcing agents such as chopped glass fibers, matted glass fibers, and asbestos; and mold release agents such as zinc stearate. Examples of flame retardants include antimony oxides or chlorides, chlorinated paraffins, and the like.

Reference examples and examples are listed below to further specifically explain the present invention. Note that the parts and divisions in the examples are based on weight.

Reference Example 1 (Production of unsaturated polyester) Maleic anhydride 2,940#, 1,2-propanediol 2.356.
F was charged into a reaction vessel and kept at 200°C for 8 hours while heating and stirring under a nitrogen atmosphere to form an unsaturated polyester (a-1).
was manufactured. The leakage was 60 and the double bond equivalent was 156. This unsaturated polyester was cooled from 200°C, and when the temperature reached 150°C, it was poured into styrene to which 200 pp, m of t-butylcatechol was added to reduce the nonvolatile content to 7.
An unsaturated polyester resin (A-1) was obtained.

Reference Example 2 (same as above) Maleic anhydride 2,940I! , 1.2-propylene glycol 806g, neopentyl glycol i, 040
An unsaturated polyester resin (A-2) with a nonvolatile content of 60 g was obtained in the same manner as in Reference Example 1, except that 2,400.9 g of hydrogenated bisphenol and 2,400.9 g of hydrogenated bisphenol were used. The unsaturated polyester (&-2) had an acid value of 60 and a double bond equivalent of 222.

Reference example 3 (manufacture of saturated polyester) 1.2-propylene glycol 760 g, cepatic acid 2
．． 020,9 and Tetrata knowledge λ Shichita Yoto 0.21
1 was placed in a reaction vessel, heated under a nitrogen atmosphere, kept at 150°C for 1 hour while stirring, and then gradually raised the temperature.
The saturated polyester (d-1) 2.37011 with an acid value of 1 and an average molecular weight of 8,000 was obtained by keeping it at a temperature of 200 to 240°C and under a reduced pressure of 1 wHg or less for about 10 hours. It was dissolved in styrene containing a certain concentration to obtain a saturated polyester solution (D-1) with a non-volatile content of 40%.

Reference example 4 (same as above) 1.2-propylene glycol 760. ! i+, adipic acid 1,460.9 and tetraptooxytitaney)
0.2. IiF was charged into a reaction vessel, heated under a nitrogen atmosphere, kept at 150°C for 1 hour while stirring, and then gradually raised to 200 to 240°C for about 15 hours at 1 mH and under a reduced pressure of 9 or less. Saturated polyester (d-2) with an acid value of 0.5 and an average molecular weight of 3,0.000 1,82
0 g was obtained, and 300 g of hydroquinone monomethyl ether was obtained.
It was dissolved in styrene containing a concentration of ppm to obtain a saturated polyester solution (D-2) with a non-volatile content of 40 parts.

Reference example 5 1.2-propylene glycol 836.9. Adipic acid 1, 4601/and tetrabutoxytitanate) 0.
2. ! After heating under a nitrogen atmosphere and keeping at 150°C for 1 hour while stirring, the temperature was gradually raised and kept at a temperature of 200 to 240°C and a reduced pressure of 1 mm HJil or less for about 10 hours to remove hydroxyl groups. Value: 14, acid value: 0.
1. Average molecular weight 8. 1.900 # of υ00 divalent hydroxy polyester was produced. 76g of adipic acid in this dish
was added and kept at 220-240℃ for 6 hours until the acid value was 14.5.
A divalent carboxypolyester was obtained.

Next, this divalent carboxypolyester was heated to 150℃'J
The reaction product of bisphenol A and β-methylepichlorohydrin (epoxy 1215, molecular weight 4
6o) icy and 2-methylimidazole i, o
Add y'i and keep it at 16υ~140℃ for 5 hours until the acid value is 6.
, average molecular weight 15, υUO saturated polyester (d-3
) was obtained, and 60υp of hydroquinone monomethyl ether was obtained.
It was dissolved in styrene containing a concentration of pm to obtain a saturated polyester solution (D-3) with a non-volatile content of 40%.

Reference example 6 (same as above) C-caprolactone 3,990g, terephthalic acid 83g
．． F and 4 g of tin dioctylate were charged into a reaction vessel, and the mixture was heated at 200 to 220°C with stirring under nitrogen atmosphere for about 10 minutes.
A divalent carboxypolyester was produced by keeping the mixture for a certain period of time. The acid value of the obtained divalent carboxypolyester was 10. The average molecular weight was 10.00 (J).

Next, this divalent carboxypolyester 5 U O9, a reaction product of bisphenol A and epichlorohydrin (
Epoxy equivalent weight 184, molecular weight 56B) 18.41 and triethylamine 0.51 were charged into a reaction vessel.
Reacted at 40°C for 5 hours, acid value 2, average molecular weight 30.0
A saturated polyester solution (D-4) having a nonvolatile content of 40 qb was obtained by dissolving it in styrene containing hydroquinone monomethyl ether at a concentration of 3 DOppm.

Examples 1 to 6 and Comparative Examples 1 to 6 Unsaturated polyester resin (70% nonvolatile content) (A-1)
, a styrene solution of a thermoplastic polymer having a carboxyl group in the side chain (non-volatile content: 40 parts) (C-1) to (c
2)% saturated polyester in styrene solution (non-volatile content 40
%) (D-1) to (D-4), zinc stearate, calcium carbonate, t-butyl perbenzoate, and magnesium oxide are mixed in the composition shown in Table 1 to produce an unsaturated polyester for curing. A resin group acid compound was obtained, and SMC1 having a glass fiber (1 inch chopped glass fiber) content of 25% was prepared.

This SMC was heated at a pressure of 50 k'; l/al and a temperature of 140 k';
℃, press molding for 5 minutes to form a flat plate (600mm x 600mm) with a thickness of 2 sugars and 4 pieces (600mm x 600mm),
A bat with a length of 15 baits (150 baits horizontally, 25 baits vertically)
0 mm, depth 50 questions, thickness 2.5 m), warpage (deformation) of the flat plate was measured, and the surface condition of the flat plate and sink mark (shrinkage) state of the lip portion were visually observed. The results are shown in Table 1.

The method for measuring warpage (deformation) and the evaluation criteria for surface conditions and sink marks (shrinkage) are described below.

Measurement of 0 warp (deformation): After the molded flat plate was left at room temperature for 24 hours, it was placed on a flat plate, and the amount of deformation from the flat plate was measured and defined as warp (ΔH).

0 Surface condition ◎: Projection performance (how well surrounding objects are reflected) is extremely good,
No distortion of the projected object was observed.

O: Distortion of the projected object is partially observed, although it is not obvious.

62 Partially obvious projection distortion is observed.

×: Obvious distortion of the projected object was observed on the entire surface.

0 sink (shrinkage) condition ◎: No sink mark observed at all.

○: Not obvious sink marks are observed.

△: Some sink marks are observed.

×: Sink marks are clearly observed.

/ Examples 7 to 9 and Comparative Examples 7 to 10 Unsaturated phase polyester resin (70% nonvolatile content) (A-2)
, styrene solution (non-volatile content 40%) of a thermoplastic polymer having a carboxyl group in the side chain (C-1) to (C-2)
, styrene solution of saturated polyester (40% non-volatile content)
Unsaturated polyester resin for curing is obtained by mixing raw materials selected from (D-1) to (D-2), zinc suderate, calcium rehydrate, 1-butyl perbenzoate, and magnesium oxide in the composition shown in Table 2. A compound of the composition was obtained and used to prepare an SMC having a glass fiber (1 inch chopped glass fiber #) content of 25%. Next, warpage (deformation) was measured in the same manner as in Example 1, and the surface condition and sink marks were evaluated. The results are shown in Table 2.

Claims (1)

[Claims] (11(a) unsaturated polyester, (b) unsaturated monomer copolymerizable with unsaturated polyester, (e) thermoplastic polymer having a carboxyl group in the side chain, (d) saturated (e) An unsaturated polyester resin composition characterized by containing a divalent metal oxide or hydroxide. The unsaturated polyester resin composition according to claim 1, which is a saturated polyester obtained by reaction.